Man I hope you read my post, i actually put some thought into answering your question
I assume you are still in highschool??
This situation brings me back to my highschool memories. I use to care what others thought of me, and afraid to do what I wanted to do. Major social anxiety for me as well but I got over it.
Heres my advice
Don't do anything you don't want to do
IE
him=hey buddy lets go smoke this joint
you= I don't smoke
him= You'll lose my respect
you= yah sure buddy go **** yourself
Just stop giving a **** what others thinkof you and you'll be so much more happier. Don't do anything you don't want to do. DO WHATEVER THE HELL YOU WANT. In the end it's how you feel.
IE
You work at mcdonalds while you are in highschool, most of the highschool jerks think lowly of you because you work there.
I'm out of highschool now and in college. I will tell you this now, I have mad respect for people with good work ethic no matter where they work. Mcdonalds, burgerking whatever. If you have the balls to do what you want people will respect you for what you do trust me.