Hi there. I'm with you. I would have probably posted on "Saving" too, but they may move your post to the "Improving" section. Let's see.
I think that it is great that you are getting yourself informed about this stuff. At least that way you can make an informed decision about what you are getting into with this illness, and be careful about how it can affect your depression. I must admit, had I read the warning signs better and seen the future I might have chosen a different path for myself. I don't want my own mental health wrecked in the process, and it takes a lot of work to not let that happen. That said, I do think there is a lot that one person can do to improve a relationship whether the other person even knows if you are doing it or not.
One of the things to let go of now is control. You have no control over whether she leaves or stays. It can happen suddenly and throw your life entirely off balance. If you can depersonalize that kind of stuff it might hurt a bit less if it happens. Turn that into a positive if you can - the letting go of control of outcomes and other's behaviors. It is actually a huge facet of buddhism if you want to read up more on such things - it offers great tools. I find that it gives me a sense of freedom and peace of mind. If I can't control things outside of myself what is the possible reason to feel bad about that? Let it go. Instant freedom.
So she is aware of the diagnosis? Do I understand you correctly? That seems potentially positive. I have gone against a lot of what is advised here and discussed the potential diagnosis with my partner. He is more open to the idea than many I read about here, and I've managed to make some good steps with putting this out into the open in just the right way for us. I simply had to insist upon bringing this into the narrative of our relationship.
I try all I can to align us "against" the illness rather than each other. I also try not to run him into the ground with it. He is very susceptible to guilt and shame (not a facet all BPD's share I've noticed in the many stories on here) so I try not to guilt and shame him and set off his extreme emotions. I am lucky in the sense that he recognizes he is "a bit crazy" and not always in control of his emotions. Although highly educated and having a great job he sees himself as very dependent on me for caring for him overall and does not want to lose that, so we are able to work with it for now. I mean, I get him to recognize there is a serious issue here, these reactions are "not normal" and we go from there. How can we make this better and get the most happiness out of life as possible? I want to keep upbeat whenever possible so I take this as a chance to practice kindness. It's free and it makes me feel good.
Also keep in mind this is a spectrum disorder so it can look different - that is one reason it took me so long to figure this all out. My partner does not have all the traits, I think, but he does have serious ones. His fear of abandonment is massive and his black and white thinking is like that eclipse you saw last week.
I am so "lucky" compared to many here though because in his white phases he really does not have a bad word to say about me. I see that a lot of people here deal with near constant verbal abuse. On the other hand, I had never experienced any verbal abuse before so it has been devastating for me. It takes me a long, long time to recover from his black phases. I am still recovering from the last major one he had in July that lasted nearly two weeks. I am still nervous and anxious and walking on eggshells, afraid of when the next shoe will drop. But I am also determined to be happy with my life under any circumstance.
I would suggest now, while you have a chance, that you also inform others in your life about what you are getting yourself into here - if that is possible. People in your life might be able to help you if they understand that you are dealing with someone with serious issues. It is great if you can have a support system for this. And if that doesn't work, you have all of us here, okay? We get this, we live it, we are learning about it and we are doing the best we can.
(p.s. Yes you can edit posts, but only for a short/set amount of time after you make them. Click on the word "Modify" in the upper right corner)
