oh, you are a smoker too ... you should switch to niccoteine gum to get your fix, becasue the drug delivery system, tobacco, is really realy toxic and a carcinogen.
im not saying anything is wrong with niccoteine though ... but ... maybe that is responsible for your mood disorder, i mean its a pretty strong drug in itself, and a stimulant, and you say you can't sleep soo I'd think it would be one of the first things to eliminate for your insomnia.
im suprised wellbutrin didn't help you with your nicoteine cravings, i have heard it to be very effective before for this.