Personally, I do not believe that much meaningful change is realistic unless
a) I feel able to talk about it with my wife
b) she is willing even to explore the possibility that a PD may be contributing to our crumbling
c) engage with me in doing something about it.
What is your experience?
Hello and welcome to the family. I'm sorry you're in this situation.
In your three goals for meaningful change, I couldn't help but notice that each of them related to you in some way. So before we got too far into this, I wanted to share that BPD is a serious mental illness that can't be "fixed" unless someone is willing to actually get help.
Even though you want that for your wife, this problem is internal within her and she must be the one who makes the decision to seek help. You can't force it, and the mere mention of it may send her spiraling. It's a much better idea to let a professional broach the topic with her so you're not viewed as the enemy.
Meaningful change can come if (a) your wife realizes there's an internal problem and chooses therapy. But it can also come from your end as well in learning how to better communicate with her, validate her feelings, and diffuse situations before they turn into arguments. This requires a lot of work on your part to meet her where she's at, and you can read through the tabs at the top of the page to get a better idea what that looks like.
Let us know what you think and again, welcome to the family.