Hello and welcome!
I'm sorry you have found yourself in this situation. I'm sure his behaviors have been hurtful, bizarre, frustrating and stressful. But, you are not alone. We all have family member or spouses wBPD, and while you can never take the BPD away... .there IS hope
The very very first thing to do if you haven't already done so is check out the lessons on this forum. The biggest thing in my opinion is learning to effectively communicate. If we can do that... .a whole lot of the behaviors reduce significantly.
Is he in therapy now? Are you?
Where do you want to go with this relationship? Are you feeling about it?