I have been on Cymbalta too, and it didn't have that effect on me. Seroquel certainly did though. 30kgs worth. Never take that.
Did you switch meds?
Nope. I took myself off them... tapered off. I was on it for 9 months or so, but the weight gain didn't kick in really until the final 3 months. It also took away the anger it was given to me for, but took away all desire to do anything at all. I didn't go out for 8 months apart from to the local shop. I hit the highest weight I have ever been in my life on that crap and still working to get it off. Think I am down 1.5-2 sizes in my few months back at the gym, but that med totally changed my body composition. This is how I looked before I went on it.
This is what I looked like just before returning to the gym.
and this is where I am at now, after 2 months back at the gym.