To counter Forever's point, you haven't talked for several days and your partner is in mental crisis.  The blame was 100% expected because she had two options- blame you or admit that she has some serious problems within.  Although it didn't go well, at least she heard you and it's given her things to think about.

I do agree with his points though, these relationships are so hard to repair long-term when a partner with mental illness begins to spiral.  Any conversations in the next little bit will likely be similar to what you just went through.  It's part of the process and it is incredibly sad.

Remember, this is the time to focus on what's best for you.  The relationship will work out or it will fail, and that's largely outside of your control.  But if you find yourself once again and begin to make healthy choices, then you're going to walk away from this a winner no matter what.  The prize is not the relationship; it never was.  The prize is getting back to a healthy, balanced life where you're not constantly under stress and worry.

A lack of assets generally makes the divorce fairly simple.  Mine took about 2 years as well (it was late COVID so the courts were very back logged) but we managed to split up assets civilly.  Like you, there wasn't much- household items, furniture, stuff.  We also had a home to sell, but even that was pretty straightforward and you don't have that issue.

In my state, I filed for a non-contested divorce where we both signed paperwork, submitted it to the courts, and saw a judge for the final ruling.  I did it all myself because again, there was little to fight over.  Why argue about stuff that's worth 5-10k and pay lawyers 10-20k?  I'd rather her take everything she wanted, and by taking that route she softened quite a bit.  I didn't want the fight, I just wanted the divorce so we could both move on. 

For me, it worked.  For many others here, it didn't.  So I'd say that a lawyer consult is critical at a minimum.

This is in the "conflicted" category, so let's briefly talk about the other side of this.  When you approach her to get your stuff, you'll likely have some level of conversation.  I can tell that a part of you wants to run, and a part of you wants to stay.  That's completely normal and most of us felt that. 

Try to have that civil conversation and talk our your needs, your feelings.  Maybe that changes something, maybe not.  The next few conversations would be the time to express that without fear.  Worst case scanerio, it goes badly and you walk away.  But you've already walked away and you've felt better because of it.  So there's nothing to lose and everything to gain in this situation.  Either she makes meaningful change or she doesn't.  I'd advise to pursue that path anyway, wear your heart on your sleeve for 30 minutes, and tell her what actually matters to you and how you've felt.

It will either give you closure or open the door to potential reconciliation.  Both are positive options.

The common wisdom is that it doesn't matter which spouse files first.  In your case, without any custody/parenting issues to blow issues out of proportion, that may be true.  No one can predict in advance.  However, the fact is she has raised the level of conflict by involving the police.

I often write that it was so astounding how my ex could be such an aggressive purported "victim".  In our case, we had a young preschooler and the divorce was all about custody/parenting.  The allegations and vitriol were horrible and endless.  The divorce process took a couple years.  So for me it was different... I felt better by knowing that I was the Plaintiff and my disordered but undiagnosed ex was the Defendant.

If you haven't started interviewing experienced attorneys, then now is the time to do so.  You need to know where you stand on a multitude of legal matters.  Laws and procedures vary from one state to another, even from one county to another.  It's far better to know where you stand rather than guess.

Now, there is a real difference between repairing a relationship (where you share information tom rebuild trust) and ending a relationship (where you restrict what you choose to share so that such information cannot be used to sabotage you).  Your lawyer would agree with that wise stance.

You may feel you need to be overly "fair" and must share with your soon-to-be ex (stbEx).  While that sense of fairness is likely strong with you, as it is with many of us here, beware.  You already know that your desire for fairness won't be reciprocated by your spouse.  As the old saying goes, "Loose lips sink ships."  Whenever in doubt whether to share any new information, consult your lawyer, therapist or even peer support here.

That was your reality check.  Quite sad but not unexpected.

Overall, I've come to a conclusion which so many have come to as well... We can spend so much time and effort in our efforts to turn around our close relationship with a person who too often sabotages close relationships when they put too much weight to emotional feelings and resist facts.

They too often simply won't or can't get past the baggage of the relationship to truly listen to us.  But... they might be receptive to a therapist who is both experienced and yet does not have a close emotional relationship with them.  If therapy starts, continues and is meaningfully applied in life, perceptions and thinking... progress is possible.  If not, then... it may be time to cut your losses.

Thank you all for the advice.
I have made a list of the bad memories and have left plenty of room to add more as they come to mind. It's honestly scary. I can't believe I have stuck around as long as I have!
When it comes to shared assets, debts, etc. We really don't have any. We don't own anything together and all of our finances have been separate from the start. We don't have a shared bank account and all of our credit cards are in one name only. Given the nature of our relationship, I have been cautious from the start.
As for getting my stuff back. Fortunately, a lot of what is important to me is in a storage unit that only I have access to. She has a lot of things in there as well. There isn't much at the place she is currently living, but it is stuff I would like to have back. My current plan of action is to have her put it somewhere I can get to it without having to go inside and then pick it up on a day I know she won't be home. 
She also took my dog and is refusing to give her back. A number of years ago, she bought the dog for me as a birthday gift. Before I left, she said because she paid for the dog it is now hers. Funny thing about this is that on numerous occasions, at times when we weren't in the same place, she has thrown a fit about the fact that she has had to take care of "my dog" and has threatened to take her and drop her off somewhere. Suddenly, it has become her dog and she is refusing to giver her back to me.
I agree that it would be in my best interest to get ahead of the game and not allow her to file first. Knowing her, I have a hard time believing she would take the time or make the effort at this point, but I know I shouldn't count on that.
It's been about 5 days of no contact at this point. I still have my ups and downs, but feel that I am in a better place than I have been in the past when going through this. The silence on her end is making me a bit nervous. I keep expecting her to reach out but she hasn't. I think a lot of it has to do with the fact that this is a really busy time of year for her with work so she really doesn't have much free time. I am concerned that when reality sets in, things could get ugly. This has been the pattern in the past. I am keeping my fingers crossed!
 

Well it didn't go well. I tried with the advice. She jumped in and wouldn't back down on everything being my fault. She said she needed to get off the phone. It doesn't look good. And frankly, this showed me how impossible the relationship would be.

A lot of useful stuff here. Thank you.
But to be clear I am not sending her money and she has not asked. We have periodically shared financial gifts with all of our kids (my husband has older from his late wife) without being  asked. Mostly directed to college funds.

This daughter has always supported herself and not asked.

My inquiry was wanting to be prepared for a possible request when she perhaps ‘hits bottom’ or has some sort of crisis. .
Again, very helpful.  Thank you.

This is great. I need to keep this handy until I learn to do it naturally.

I've been listening to an audio book on strengthening our relationship and one of the suggestions it has is giving my SO a compliment a day for a week. I know for a fact that Words of Affirmation are her love language but this is something that doesn't come naturally to me. I can be encouraging, show support, and I tell her multiple times a day that I love her. The times I try to go beyond that she'll hit me with a "tell me something else" and keep pushing me until I freeze up and it usually ends with both of us upset because, as she says, "you never say anything nice about me" and I end up feeling like I'm not good enough that I can't give her what she craves the most. Alternately, she'll say "you don't have to say that", which stings just as much.

Anyone have any tools to get through this kind of situation? All I've got is to not say much and I don't feel like that is good either.

I've gone through this myself. I've pushed a few times for my wife to see someone but never by telling her that she needs to be the one to go. I've suggested going for couples counseling and framed it as my needing help. That, at least, went over well enough, even if I didn't actually get her entirely on board. I have on 2 separate occasions started seeing a councilor on my own when I have become overwhelmed. Through seeing improvements in myself she has at times mentioned that she was going to look into seeing someone herself but has not yet. When she brings it up I'll usually say something encouraging without pushing. Something like "we could all use help sometimes" or "everyone should see a therapist from time to time."

Don't be afraid to seek help yourself. The times I've gone have been incredibly helpful.