You're 20? You have your whole life ahead of you, get back on the grind and make it happen! It may feel hopeless now, but I assure you it's not. I'd bet you have skills that other people would love to have, you just need to figure out how to better apply them.

Don't give up, hard work pays off, I was in your exact situation or worse when I was your age :) (I'm 23 now and have turned it around)

Oh, and parents say things like that, ignore or fight them, it doesn't matter, just don't let it get to you. If you have friends that make fun of you, you are either misinterpreting what they are saying or they are not actually your friends. In the latter case, get rid of these people, they are harmful to your psyche.

Get in touch if you need more help, talk to the people around you too, people care more than you expect