I should be studying right now, but everytime I sit to study, I can't sit there long enough, I want food even though I am not hungry, I want to watch TV/youtube, self-pleasure... etc...

No matter what productive work I want to do, I will try to not do that and do something which gives me momentary pleasure. I want to masturbate, eat lots of food even though I am not hungry while watching TV/Youtube and I don't seem to be able to break the cycle and it's destroying me. How can I break the cycle and do something good for a change instead of pleasuring myself in the moment meaninglessly?