How can I prevent myself from overeating?

To answer. You should probably be working with a dietician on portion control and a counselor on the emtional porblems that influence you to over eat. You may need to consult other professioanals to.
Seek help. A history of depression or other mental illness could lead to overeating secondarily. With adequate treatment, your overeating could stop. Otherwise, adding fiber to your diet will curb your appetite and reduce the tendency to overeat.