Welcome back to SR!
Have you ever been evaluated for being bipolar? I was treated for depression for several years and tried all kinds of different drugs. None of them worked for very long. When I was diagnosed as being bipolar, my psychiatrist told me that many bipolar people are misdiagnosed as having depression and that being on antidepressants can actually make the situation worse.
I'm no doctor but it's just a suggestion.
Best of luck!