This is a tough place to be in. Since you are on meds., I assume you have a doc. I wonder if you are bipolar. The reason I ask is that I am bipolar and the way we found out was that anti-depressants always made me worse instead of better, and believe me, I tried them all. The other reason I wonder about this is that you are currently taking Seroquel, which is used as a mood stabilizer. I take Seroquel and I love it. I take it at night to help me sleep and it works wonders. I also take Lamictal (another mood stabilizer) and Wellbutrin. This is the combination that has helped me the most over the years and I finally feel really good.
I never thought that I was bipolar because I never had the typical "manic" episodes that you read about. But I later realized that I did have manic phases, they just weren't as pronounced as you usually read about.
Anyway, sorry to drone on about that, but here is my point (and I actually do have one). Once I got on the combo of meds that was right for me, other things in my life got better too. I started going to a gym, which I never would have done before. I figured that if I was paying money, it would make me more accountable. Anyway, that led to doing cardio at home and that led to eating better.
Maybe you should talk to your doc about your meds and see if there are any other meds you could try. It may or may not be the answer, but it might be worth a shot. Best of luck to you.