I feel stupid and selfish?

Ok i'm not the kind of girl to be selfish or jealous, but lately it's all i feel . . . in my group of friends i have 2 groups my age and then the younger. We're all going to church camp together (which makes the feeling even worse!) bt the thing is that Ann (nt real name) doesn't even go to our church and my other friend Amber (again nt real name) does. It's like the only thing i get to do with Amber without Ann and i feel like i'm losing Amber to Ann even tho i kno they're both my friends. They just seem to be spending more time with each other, and no matter how i try, they just don't seem to want to hang with me. Then in the younger group, all the girls pair off in groups, and i feel like i don't fit in anywhere . . . . it sucks . . . . i don't know what to do .. . . Help?

Thanx!