Greetings, and than you for your question. I see you are offline right now, but allow me to offer that there are several options to dealing with antidepressant-induced weight gain: (1) Switch to a different antidepressant and see if it works as well but without the weight gain; (2) Add another medication to it which will reduce weight gain by reducing appetite, such as Wellbutrin or Ritalin; (3) Dietary and exercise modifications, such as regular exercise (could be as simple as walking a mile a day) and eating multiple small meals during the day instead of a few big ones.
Weight gain is common in these medications, so all of these are reasonable options to consider.
Hope this helps! Please let me know if I may be of further service.