if low serotonin causes the brain to crave food, how do you restore normal serotonin levels?  What are the molecular components or the molecule that mimics serotonin?

Being depressed for most of my life hasn't been fun, but a huge weight gain has only made my condition worse. 

 I have stopped taking any ssri, but am taking trazadone, wellbutrin, klonopin (have gone from 3/day to 1 or 2, and weaning myself off of paxil cr.

I thought I could just 'diet', but it's like my brain is always craving food even if I'm full. 

Psychiatrist seems to know nothing. 

What made me gain enough weight to be called obese was Seroquel which I was taking for my insomnia.  (does that play with serotonin as well, and if not, by what function does it make it possible to put on 60 pounds in 2 years?) I've been off it at least 3 months but the damage was done.  It seems I'm on my own to lose this anomaly of a stomach that is simply enormous and up high under my breasts.  I've never gotten fat there even a tiny bit, that's just not a place I ever had trouble with, and it's hard as a rock.

What brain chemistry did that tool with and how can I restore my brain chemistry from what Seroquel has done. 

I've been researching and it seems that if I restore the serotonin that has been depleted by these medications, I might recognize actual hunger once again and be able to lose this weight in a healthy way. 

I'm desperate, it's all I think about.  I NEVER go out unless I have to market and I go late at night, I don't want anyone looking at me.  I'm only five feet tall and I literally hate myself.  If there is a solution to restore my brain chemistry, I need to know what it is.

Mostly I'm interested in what the mimicking agent is in those pills to ruin my instinctive brain functioning.

PLEASE HELP