I see you're going through something strong, resilience. Society, family, friends, can make us feel bad with their perspective, the important thing is the value you give yourself. The physical image is a game that you can alter. For example, I have a disabled left arm, it's painful when I go down the street and some pretty girl looks at my arm. I don't know what to tell them, I'm very embarrassing. I'm 23 and I identify with what you write.
But that can't stop you, I recently started exercising and reading more often, my lifestyle is very different, I don't like parties I prefer to be at home reading or writing. A lifestyle different from others that makes me happy. Don't let this tear you down, look you're a great guy willing to help, something not everyone does.
I know it hurts a lot, but the pain transforms you, changes your perspective of things and makes you act differently from others, if you learn this, it's an advantage that induces you to success. Come on, don't complain, be an example, a warrior. I bet you have a list of strengths, only you see everything with the glasses of sadness. Above those moods, if many can live with disabilities or terrible illnesses and are still happy, consider it a test. Be yourself and let others suck on it.