I'm bulimic, need 2 lose more weight fast!?

am bulimic, not afraid to admit it...I'm not a skinny one tho...I am quite plump. I weigh about 150. I lost about 50 pounds last year because of it. I kind of got away from it for a while because I was content with my weight. Recently I have gained about 15 pounds back and its killing me. I am back home for a while and I see my skinny *** sister, )that my husband constantly eyes down by the way) waltzing around here, I just need to kno a faster way to get the weight off. I am on birth control which I know has contributed to my weight gain. Do I need to stop them and then try? IDK...I am desperate..Any ideas?