Kat, your lone wolf thought is exactly how I felt. Much as the wording has such strong connotations, there are some days when I feel like the right word is, victim.
When we discussed the differing perspectives of what exactly was happening, I felt that this change was a choice in expression, a lifestyle. My husband views this change more like a chronic state. He compared it to terminal cancer. Using that analogy, when I'm upset I feel that leaving is a matter of choice, his or mine, but he sees it as almost abandonment. So, if we stay, we are judged to be "that poor woman" (so very broad in generalizations here...) and if we go, we are judged by the community that supports our loved ones to be heartless (again, generalization). Damned if we do and if we don't. As far as I'm concerned, we lose no matter what choice we make. Can the same be said for our partners? I don't know.
I wish, Kat, that your therapist could be more help. How are your local support groups? Any way that you might be able to re-recruit your best friend to support you? It's so vastly unfair that our partners make a whole new support network when they approach the community, but we are forced into isolation because our partners aren't ready to "come out" yet. I feel like we deserve to have a support system. (My husband reasoned that's what the community SO support groups were for, but that is utterly not the case.) For now, there's me, if you feel the need Kat. You can message me if you'd like.
Separation may not be a bad idea. Space, time are both things you might both need to gain perspective. I understand that I only get to hear your side Kat, but if you guys aren't getting along and you're clearly hurt and angry (meanest person...etc...) why won't he give you that space? (You aren't mean at all. Quite reasonably upset, really.) Maybe not a legal separation, but a weekend to visit someone you really miss?