weight gain

I've gained so much weight over the past 6 months it's crazy!! I think it's because I switched to a stronger birth control but any tips on getting this weight back off? This has made me extremely depressed and filled with self hatred. I do not fall into another spell of anorexia though. Any tips? I'm on the pill so I'm not sure what else I can do. I go to the gym as often as I can and have recently cut a lot of foods out of my diet