Sky101, I wish I knew what to tell you. I'm so sorry to hear your husband threatened you that way - blackmailing you like that is just wrong, and I should hope that if he did post it, people would realize how disgusting it is to post something like that in the first place and support you.
It's hard to have a partner who doesn't support you. He clearly doesn't understand what it's like to have BP, let alone MI. Ignore the hurtful comments the best you can, and if you need to, don't be afraid of the hospital. I've gone before to get stabilized and it was a good decision for me at the time.