How is your health / fitness level? I felt a bit like that when I was up at around 260 lbs (I'm 5' 11" tall). I started watching what I ate (I used a food tracking app to monitor caloris in and out and come up with a realistic plan to get to my supposed "ideal" weight which is 185-190 lbs and started some exercise - first walking around the block, eventually jogging and some exercise DVDs in my living room. As I shed lbs, I started to feel better and better, my interest in various things perked up, and I feel like I'm even more social now. Maybe this would help you too? Just a thought.