I'm in so much pain, imagining how lush it was together, wishing for the past, seeing him on insta sweet talking to other vulnreable girls who are all over him. I have cut contact except this, I am self destructing :'(
I understand this pain and am going though it very similarly right now. I have gone NC with my ex uBPD gf for just about 3 weeks now, but I have found myself looking at a mutual friends FB page just to see if she has posted pictures of them going out since. It is very self destructive. It is the OCD that comes with the end of the break up... .any break up whether with someone with BPD or not. The problem is that we go into a sort of memory trans where we only can remember the good things and when we do think of the bad things we dismiss them immediately. As we know when you are painted white by your BPD partner... .things are GREAT! So when we are spending are time remembering only those times... .damn it sucks and why did we leave them again? Remember why you did choose to leave and that those bad times should not simply be waved off with a shrug of the shoulders... .they were bad! At least in my case I know they were... .yet somehow I still miss her... .it's crazy!
All you can do is find other things to do with your time, "fake it until you make it" has a lot of truth behind it. Fake being happy and doing other things, going out with friends, and eventually you'll find you are happy again. Also, highly recommend a therapist if you don't have one already. Anyway, I feel your pain, I really do, hang in there.