Lazy and overeat. In my opinion, I should be getting fat. Why am I still doing this?

You tell us. You know the problem. You know the negative outcome of your choices. You tell us why you're still doing it. Is it emotional eating or just gluttony?
Depression? Good question why are you doing it? Do you have an underlying disease that contributes to inactivity? Your initial symptoms sound to be depression and i certainly would speak with a physician before things get worse for you. I dont know you but find a purpose to get going and start exercising with the first goal to not getting fat since that will just lead to more problems. Good luck.