summerfreeze
that's a long time to be dealing with a tough condition like that - coming here to look for answers shows that at times you are still able to instinctively do things to take care of yourself. Keep looking. I hope from the variety of possible causes that have been posted here you can find a direction to continue the search.

To add my own 2 cents worth, from my own experience, if my cortisol levels get too low I get to a point where I don't care about anything - not even my own welfare. For me that state is a warning sign because unlike most people my body no longer produces any cortisol naturally (due to auto-immune condition), I have to replace it artificially. Research has been done on the connection between low cortisol and depression.

If you have copies of you previous tests check back and see if your cortisol levels have been measured. If not it may be worth checking. Ask them to do the 8am fasting test. You're probably also aware that having been on so many different meds there may be interactions and long term side effects.

I don't have much medical knowledge but happy to try and answer any questions. All the best for making progress.