I feel for you. I’ve been there. It was with the wrong person, but not because he was bipolar; our bipolar-ness lent an incredible connection and understanding to the relationship (which should never have happened since he was married — I will probably always feel terrible about that). But I’ve always thought that one bipolar meeting and loving another feels like maybe a “domesticated” tiger would feel, after years in human society, upon meeting another tiger for the first time. You suddenly realize you’re not utterly alone, not the only one of your kind. Seeing those familiar stripes on someone else is so heartening, so comforting and at the same time thrilling and a bit dangerous. You know this tiger is capable of hurting you and vice versa. Friendship and love between tigers is extremely powerful and therefore must be treated carefully. As you said: self-care comes first.