Hi Golorolo,
This is the right spot if you are interested in potentially bettering the relationship. There is also a legal section of the board you can check out here:
Family Law, Co-parenting, Custody, DivorceSo you think there are elements of BPD, Bipolar and Depression? How is couples therapy going so far?
I am not an expert, and don't know what part of the world you are in, but I think it is very hard to get sole custody. (My SO's ex wife did an international child abduction and he wasn't able to get his kids back though he fought tooth and nail for them. It is shameful and shocking to me how little the legal system gave him actually, and how little he was recognized as adding anything meaningful to their lives aside from financial support. She managed to steal years and years of time that he and the kids should have had and nothing can ever repair that. This saga was a huge contributing factor to why he's so, he's not been so well... .well, he has a lot of symptoms and I gave him a lot of room because of this.) Keep in mind that we might want the legal system to do versus what it can and will do are often very different things.
In your case, it would be good to start documenting and preparing incase you do choose to take that path.
Anyway, reading over on that board and posting there if you like, should give you a lot of insights!
with compassion, pearl.