Are you sure it is actually a physical side effect from the celexa? I used to eat to calm my nerves. I did this all the time and a few months ago I had a sort of mental breakthrough and lost almost 15lbs in 2 weeks. I no longer felt the need to constantly eat. So just make sure that it is a physical side effect and not a mental issue.
Good luck
Are you in therapy? Because medication doesn't cure, it just helps us cope. As for quitting, you can do that any time you wish, just do it slowly, taper carefully to prevent a bad withdrawal, and in a month or two you'll be off. But if you haven't solved your underlying problem, you'll still have it, and be back on Celexa or another med that might not work as well for you, especially given the long period of time you've been on the med. Wish I could help you with the weight, but I had the same problem with Paxil and I never solved it, and I exercise a lot and eat pretty well. I've heard that Prozac is the best for not gaining weight, but whether it will work as well or not, who knows? Didn't do anything for me.