I'm on Citalopram too - I switched to it fter being on Fluoxetine for a year and that stopped working. I'm on a quite low dose I think at 10mg, but i share the fear of coming off it. In my case because I do not function at all when my depression is in the driver's seat. I quit four college courses because my brain just would not function for studying or doing anything that required attention paid to it. I've just finished an access to uni course, which I'm starting in September, and even though I feel pretty well lately I'm not coming off it in case I screw up my university degree!!
As for the weight problem supposedly caused by antidepressants, I started to lose weight steadily when I went on Citalopram because of my incresed motivation to change my lifestyle. So, I wouldn't say that you coming off it would necessarily facilitate weight gain, unless you have a depressive relapse which causes you to comfort eat or lose interest in your diet and healthy lifestyle - which can happen. But if you don't forsee that as a problem, then it would certainly help your wallet to come off the meds!!

Good luck with whichever you choose.