Do investigate the lawsuit option. I think you could get a LOT of money. Do not put this off...investigate this, please! You were seriously wronged and need to get some repayment from the college and also possibly from "x" for your suffering and abuse ("x" probably doesn't have much money, so a lawsuit is kind of pointless wiht him, but the school has tons of money, I am sure).
And I have been thinkign about what you described, and it is almost like molestation. If you were a female and they did that to you, there would be no question about them pursuing it as a sex crime. They may not have performed any sexual acts on you, but basically what he did was sexual humiliation and torture...stripping you and exposing you...while attacking you...and those people who cheered him on and took photos are just as guilty. Just because you are a guy doesn't mean it isn't a sex crime. You were violated. And from the feelings you described...those also sound like the feelings of someone who was a victim of a sex crime...to me at least.
And you can lose weight. Maybe you are so overweight you should consider a gastric bypass surgery. Check out this google link for relevant web sites:
http://www.google.com/search?hl=en&q=gastric+bypass+surgery&btnG=Google+SearchThis woudl basically make it so you can only eat a small amount of food. Thus, you are forced to diet, and people who do this usually are massively overweight, and they almost all do lose 50-100 lbs. or more in teh first year...mainly just because of dieting due to this device. It really does work! If you are willing to give up the food you love...this could really help you to lose a lot of weight! I'd say to do diet or exercise instead, but if you are convinced that is impossible, have the gastric bypass surgery.
You do not have to take your shirt off in a gym. Most guys at the gym I go to ... do not. You are there to work out, not to be models.
You may get thigh chafing, but once you get thinner...that will stop. Just put up with it...no pain, no gain.
You CAN lose weight. You CAN be skinny. You will only stay fat if you decide to. It is your life, dude; you can be pretty much whatever you want, within reason, if you work hard enough to make your goals realities.
There really is no need to go to the gym. What about going on a walk somewhere? You do not need to run. Walking burns almost as many calories as running. IT is not how intensely or hard you work out...but the time you do it, mainly. So don't feel the need to run--just start taking some walks...for as long as you can handle. And just so you know...when you are really big, you burn a lot more calories doing a particular physical activity than does someone who is of less weight--this is no BS--i can refer you to a link that supports what I said, if you like.
When I started walking and was still massively obese, my legs would hurt and I would get tired very easily. Now I can walk pretty much all day if i want to--though of course I don't. Your legs are just not in good shape...once you walk for a while, they will adjust to it and will not hurt so much.
What about getting an exercise bike? You don't have to even walk with that...you can sit...and you can do it in the privacy of your home. That might be something to investigate.
There are lots of ways to exercise, diet, etc., to lose weight, and I know you can lose the weight. You just have to find what works for you and stick to it. All it takes is a lot of time and hard work--but if you put in a lot of time and effort, you WILL get results. Try it...prove me wrong.
I'd lose the weight just as a way of saying F--- you to all those people who tortured you and called you fat. Show them that you control your life.