I have BPD. I agree to some degree that hospitalization doesn't help. In my experience, it just delays the inevitable. Life still goes on when you leave. Right back to where you started. But it can also calm you down for a few days to allow you to hopefully not be in such a dire frame of mind.

For chronically suicidal people, I believe that hospitalization is necessary even if they have BPD. It's a safety measure. You're no better out there than in, so might as well be some place safe that meets your basic needs.

I think the main issue here is not hospitalization. It doesn't seem like you're using your support that you do have. Instead of giving into your patterns, why not try to follow your cm and Ts (when you see one) direction. You are already unhappy. Try something different?