Terrible weight gain

I was on birth control pills for 6 years with all of my doctors telling me that it wouldn't hurt my body. Last year I could tell it was just hurting me and making things worse. I didn't know about all of the symptoms after I got off of it. I went through high school the same weight around 160ish I graduated June of 2014 I went away to school in August. I then went off of my birth control, I started gaining some weight slowly and thought it was just my change in diet as it wasn't the healthiest. I completely changed my diet and went back to everything I was doing before and still seemed to be packing on the pounds. I did some research and the most common thing after going off of the birth control I was on is horrible weight gain. I got engaged this past August. This is supposed to be one of the happiest times of my life but looking at our engagement pictures I can't help be disgusted with myself. I am no longer confident, or happy with my body. For a little comparison there's a picture of me in Sept of 2014 and then just last week. I went from around 160ish to around 215/230 being my heaviest ever. I just need some tips on how to lose the weight.