Sounds like you may be depressed. Have you talked to a psychologist about this? There are also several types of anti-depressants, so if one doesn't work, another might. I know it sounds dismissive, but research has shown that regular aerobic exercise can have very similar effects to anti-depressants. That may make you feel better. Also remember that anti-depressants take at least two weeks to fully work (they don't really know why).

In addition, have you had a full physical in the last 18 months with blood tests and everything? Some medical conditions can cause depression symptoms, along with symptoms of your other conditions. Make sure your thyroid hormones have been tested.

Don't give up on finding the answer. I hope you find it soon and start to feel better.