Hey, I'm sorry to learn that you're having a rough time. Pardon my ignorance, but I actually just learned about the condition aspergers from some redditer who guess what, manages to have his successful career, a marriage, and a few friends who share the same condition!

To tackle your issues, I suggest:

Weight: exercise. I promise you'll feel much better if you exercise regularly. You'll look better, too, with a tone body and a healthy complexion. That's actually about the best you can look naturally.

Lack of social skills and knowledge which prepares you for the future: Read -- everything. Grab a random book and start reading. Finish one, then move on to the next. Chances are that, over the time you'll become fairly well-rounded and gain some insight about human nature which in turns give you a huge advantage about interacting with people. You're only 16 and pretty much stuck at home. Books will be your vehicle taking you beyond where you're. You'll see a huge change in just a few years.