I don't have any additional advice, but want to post my support for you right now. I'm so sorry you are going through all of this. I think we have all felt a bit of the feeling you have right now of being backed into a corner with nowhere else to go. It sounds like Marg has some good ideas - it may take some drastic action on your part to turn things around and get yourself the assistance that you so desperately need.
I also vote for a good cry. Sometimes the release is overwhelming. Some of my best self-motivational talks have come in the middle of a good cry.
Many hugs coming your way.