I've gained 120 pounds in 3 years

I don't even know where to beggin to lose this weight. I started by getting rid of all my thin girl clothes. I noticed that when I have something then get rid of it I'll end up using it again lol. I hope that I can start losing weight soon. I know that the weight gain has had a lot to do with my depression. I'm going to try to get out of it. And I will be back to myself soon. I know I can do it!! I will do it!!