I'm afraid you might not get the best advice here on this site as it is a UK site and you sound as though you are US based.
Do you have a sympathetic teacher you can ask for help?
Alternatively, are there any after school activities that you would enjoy that would get you into the company of like-minded people ? Dance classes/clubs or art classes/clubs for example? Then you would have a circle of friends closer by than the ones you made at camp.
You clearly can make friends with people as you have done at camp, so the problem does not stem from you, just some inconsiderate nasty types who need to look down on someone else to build themselves up.