Tino's right though, it is a low hanging fruit, however that doesn't mean your moral standpoint is unjustified.
As for screwb, or anyone else in his position. You've admitted to yourself that you have a problem, you understand that you are overweight and that you're not sociable. You understand that these can have drastic consequences if you don't change. But guess what the first step to fixing the problem is admitting that you have a problem. I don't know what physical conditions you have but talk to a doctor, there's probably a free walk in clinic. Given you're medical history they'll tell you the best possible way to get in the best shape of your life. As for the mental side this one is a bit trickier I'd imagine. If you mention this at the clinic they might be able to refer you to some psychiatrist, I'm not sure. The balls in your court.