Hi there. I totally hear you about wanting to know why. One reason they may not be telling you what they think is wrong is because they just don't know. How exactly non-reactive depression is triggered is still largely a mystery.

I haven't found therapy to help with the depression directly, but CBT was enourmously beneficial in helping me come to terms with the fact that I didn't cause this and that my brain is lying to me when it tries to tell me that I'm a bad person and worthless. CBT essentially trains you to consciously "catch" irrational thoughts and substitute rational ones in their place, which in turn helps your behavior. Investigate it and see if it's something you think might interest you.

Lastly, trying a lot of different meds isn't necessarily a bad thing. Maybe one will work for you, after all. What I would be concerned about is a doctor who doesn't seem to give a damn and isn't responsive to you when you have concerns (I've had that type before).

It sounds like you've tried hard to find a solution. Keep it up. You're worth it.