My girlfriend and I were talking last night, and she mentioned something which I think sums up the reason why we're the ones who suffer the brunt of the isolation. We were discussing that she's not been to yoga or running in a while, and she said it was my "fault" (which, yeah, great to hear, I get her meaning, but sometimes her choice of words could do with some improvement). Basically, she used to be in a routine, she could interact with her friends when she wanted to, she'd take care of herself, do what she needed to keep her mind going. Now I'm on the scene, and while she's admitted she's happier than she's ever been, I'm also messing everything up. Beyond the unintentional triggering, she now has good feelings and good emotions which she has to deal with, that she's never had before. As such it throws her out of balance, so she pushes me away at times, while also meaning her routine is screwed. But. She still knows how to cope with her friends, with colleagues, so she's still able to message them.
It is hard at times (especially when I don't hear anything from her, but see her posting things on Facebook or something) but end of the day, she needs to do what she has to to take care of herself, just as I need to do what I need to do to take care of myself. I think that was one of the first bits of advice I got on this website - she has managed this for years on her own, she knows what she needs to do to take care of herself, while I may worry about her, and want to help her, I'm an addition to the equation. I have to trust that she can do what needs to be done to look after herself when she isolates, because she always has before. I know that doesn't help make the feelings of abandonment or isolation, but that will come in time. Just use the opportunity to focus on yourself, go to the cinema, hang out with friends, explore where you live, something that works as much of a distraction as it does as something to look after yourself.