Why can't I be myself in school?

[Sky]

(warning, this is long. I'm sorry ahhh.)
The thing is, there's a very low amount of people at my school who I feel like I would actually fit in with. I'm not trying to sound rude, but I'm honestly annoyed by a ton of people at my school because over half of the people are whiny and socially awkward and just different idk it annoys me. Then there's the people at my school who i actually could fit in with if I tried. I get along with so many people from out of town who also hang out with the "cool kids" at my school, which is a very few amount. I'm talking about the people who get a lot of likes on their pictures and are chill, you know what I mean?
I get a lot of likes on my pictures from people out of town, who are close with the "popular kids" at my school because I get along with them too but if this makes any sense, I'm not exactly cool at the school I go too. But kids from other schools think I am idk. I don't really know how to explain it but I'm really upset because at school, even if I'm surrounded by people who are all chill, something takes over and I become not chill, like I can't be chill and just have a good conversation. I let them walk all over me, tease me playfully basically and it's like I'm trying to put up a front simply for them to like me. But the truth is, it's not me. I know they like me but at the same time it's like they underestimate who i really am as a person. I can't be myself. The person I am with all my good friends from out of town where I can actually be myself and chill, and the person I am at school who is whiny and basically socially awkward, are two different people and I hate it so much. I'm really upset about it. I come home from school and I go on facebook and I'm connected with all these people from out of town that I even hangout with on the weekends and I have all these really good friends who tell me I'm so pretty and all these great things. I tell myself over and over to act this way in school. I tell myself if I could just be myself and drop the act of being "little" or "cute" or "a push over", and if I could just prove to them that I really am a decent person with a decent personality, then the people at my school would like me. Idk really, it's so hard to explain hahahaha. But I'm really upset about it. I don't know how to stop acting this way. I don't want to feel little anymore when i go to school. I even hangout with the cool people from other schools every weekend. Those people that are "facebook famous" and just really great people. I'm so underestimated in this town. I would move if I could but that's not an opportunity to me. Whenever I try to act like myself in person, I get called weird by the people at my school when really all I'm doing is acting like all those people that I like who are chill from the city and laid back people that are even the cool group of people from my school like.
I don't know. My voice is little at this school. I'm barely noticed. I smile all the time. I get pushed around. I go through a lot. When I'm out of town, hanging out with my real friends, those people that are friends with the people from my school, who I am not because I am known to be "different" by them, I'm accepted and I can be happy and I can be the funniest person ever, I can make them all laugh and smile and have a good time, and I can give them really good advice. Complete. Different. People. Do I have like a phobia or something? How can I stop this? It's ruining my life to be honest. I can't stand this town because of who I'm known as in it. Please help me.

[Edward]

Bi polar lol jkjkjkjk but maybe you are dumber around your friends?