I am sorry this is happening. You've been dealing with this for such a very long time now. I have a friend and former coworker whose W was bipolar -- she destroyed both of their lives with her mania (she refused to stay on her meds) and cost him his job as well (long horrible story); in the end he had to give it up give his W the D she demanded.
I have another friend and business colleague whose W also suffers from manic depression. By contrast he has put a lot of his faith in God and been through hell and back with his W. He has the patience of a saint and his W knows this -- it is a constant struggle for the both of them and their four kids, but they work very, very hard to keep an even keel and they have managed to stay together despite the turmoil. It helps that both of them are both strong in their faith.
Joie mentioned that I go to divorce support group. I go to a local church that is hosting a group using the DivorceCare program (http://www.divorcecare.com) , an international faith-based course of 13 weeks for those divorced or separated. We meet once a week, have a short devotional, watch a 40-minute DVD and then have a 20 minute discussion afterwards (which often continues a bit longer afterwards). Our group has also started meeting outside the regular meeting for various social get-togethers. I don't know if this particular program, which I highly recommend, is offered in your area, but there are likely several other groups and programs aside from this one that might be available.
