For the vast majority of people, it wont matter what school you go to. I shit you not. It doesn't even matter what SAT scores you get. Once you get into uni, nobody cares about your SAT, only your GPA. Once you graduate uni, nobody after your first job cares what school you went to, only your exp. (and sometimes the first job doesn't care too much about what school you went to anyways).
Does going to brown mean you are smarter then if you went to UC-Berkley? There are good non-ivy's too. What's in a name other then something you could brag about (that really nobody cares about?). When do you stop needing more then other people? Does it matter how much money you make compared to ______? Or drive a nicer car? Find a meaning in life other then school or work. Those are necessary for life, but they should not BE your life. Don't sweat it. As long as you don't get caught cheating or breaking the law in a job or something, it's not going to make a significantly big difference in your life, as long as you put in the work to get through it.
Re: socially. Bro go out and make friends. Hang out with people in groups. Be less self-conscious. I think part of your whole problem with your life is that you are too damn worried about how other people think about you, how other people look at you. Fuck that. It's about what makes you happy and what you want to do. Who you are. I'm not saying that cause you dont care what other people think you can go out and start stealing shit, but really, just be comfortable with yourself.
You don't need to worry about whoever you are with. Just worry about having fun. The more you think "what will they say if xxxxx" or "what would they think if i xxxx" then the more you just do nothing and lock up. Let it come, just do whatever you do when you are with a bigger group of people. Even in group interactions you arn't really interacting with EVERYBODY at once, but having a bunch of 1v1 interactions at the same time. You can definitely do it. Just lighten up a little.
Re: health.
Man, nothing comes easy. I used to think I was invincible cause I played a crapton of sports and could stay in tiptop shape without working out. After I stopped playing I'm fat (not really but....yea) and I realized that you have to work out and be active for good health. Not gonna lie, working out isnt easy; its hard. But you need to motivate. Otherwise nothing will change. Do you like being fat? Do you dislike it enough to do something about it? If you don't dislike it enough, then be comfortable with it.
Lastly, life sucks. Most people are only looking out for themselves, no lie. But there are some people (people like me) who derive happiness from other people. It's nearly impossible for me to be happy cause something cool happened to me, it only works when people around me are happy. It only works when I am helping other people be happy. There ARE people out there that care, they are just hard to find. And they tend to network to help each other if they get too sucked in to other people's problems. Find one, find a bunch.
Its true though that your happiness or misery generally mean nothing to other people. So stop caring what other people think, and find what makes you happy. Who cares if they think you are crazy, would you rather be miserable instead?