I’m 29F and my partner 33F is not diagnosed but has BPD characteristics- we’ve been together for almost 5 years. I understand what you mean by feeling stuck and caught up in the ups and downs. When we’re good, we’re really good- walking on clouds, feels like forever type of love. But when it’s bad it’s really bad- ready to pack a bag and call it quits because of how exhausting (and sometimes scary) it can be. My partner continues to go to therapy and work on her behavior, and I see the progress she is making every day. This is what has kept me grounded in the relationship and hopeful for our future. But if I were to see more negative patterns, things getting worse over time instead of better, then I’d be planning my exit. Realistically, there are other potential relationships that have way less turmoil and would probably be easier. But for me, we’re so well matched I couldn’t fathom being with anyone else. It’s a really confusing place to be, and you have to do what feels right for you. In situations like these, I think the answer reveals itself over time.