...
I am working and my wife is not. She is due to start college next week though. ...
Careful with this; college could be an excuse to avoid work, and a very expensive one for you if you're getting stuck with the costs of her college education on top of all your household expenses. I've seen people in my life stretch college or graduate school out for years and yet when they graduate they're
STILL nothing but a burden on someone else, but now with the added "bonus" of all the debt they accrued while in school.
Your situation is as complicated as any other with young kids involved, and while it may seem overwhelming to think of a way to separate and make it work, note that you don't have to; a court typically does that. I think this is why seeing an attorney for a consultation is so worth it. They can explain to you the local rules and the likely outcome of your case. This does wonders for your peace of mind & takes away the scariness of the threats around divorce pwBPD love to make.
At least where I live, the standard divorce outcome was not too bad & it was helpful to have seen an attorney and gotten this advice b/c what my then-BPD-wife was telling me what would happen in a divorce amounted to a fantasy world of
what she wanted to happen not what the law would determine.
You don't have to figure it all out at once; break it into steps and figure those out in turn. Get legal advice, explore living options for the separation, etc. get your own bank account separate from the soon-to-be-ex's, etc.
And at the same time, preparing for divorce doesn't mean you have to go through with it. You can work on bettering the relationship for as long as it lasts. And if things do improve and you're content enough to stay, then you can stay! Consider preparing for the divorce as an insurance policy though, insurance against ensuring that you're not trapped in an unhealthy or unsafe situation simply because you don't know how to get out.
Just be mindful that your preparations remain secret!