I CANT STOP. hELP ME PLEASE.?

I used to be happy. I used to be healthy and fit. I have become dangerously obsessed with food. It is all I do and think about. I don't know what to do anymore or how this happened. Mcdonalds just about ruined my life. I gained 60 lbs in one year. I NEED TO STOP. Please help me. What can I do? I need to stop!