My laziness and attitude is keeping me from being happy?

I'm 22 and I'm 5'7 and weigh 200 lbs. Its amazing that I've let myself get this way but it happened from over eating and laying down all day everyday watching tv week after week which has added up to more than two years. It sounds crazy but yeah unfortunately I don't have an active life. I worrie about what everyone else is doing and it adds to my negative thinking. But yeah a job agency is helping me find a job and I'm somewhat studying for my GED. I figured the weight thing is a start to gaining confidence but I can't seem to start and if I do its only for a day and I don't continue till weeks later. I'm choosing to live this crappy life and I can't seem to figure out why I don't want to break away from this. I'm a good looking guy who is capable of more( I say this but it doesn't do much for me) I know how to change my life I just don't know when its gonna happen.