How can i fit in? and have FRIENDS! :(?

Hello, i'm 15 and i have this problem. i dont think i fit in. i cant get close with my friends. they're just my friends. we only say hi to each other but i dont wanna be shy and i wanna hang out with them more. and get closer to them. my bestfriend and i go to the same school but she NEVER comes to school. so i always feel like a loner. and yes i am a loner, cause whenever she's not at school, i act like im sick and i get my parents to take me home. only cause i feel alone and i feel like i have no friends. or i spend my lunchtime alone. in the toilets. i feel like a loser. and the thing is i used to be very close with my school mates. nothing really happened but we're not close anymore. and i know they're not the best people but i just wanna get closer to them. dont wanna feel like i dont fit in anymore. and i think im a bit shy too. how can i stop being shy and start being close friends with them? and i think i dont talk to them much because i have an accent? i know they wont tease me but i just dont feel comfy talking to a lot of people cause of my accent? and when i talk to them i just dont have anything to say at all? :S pleasee help! :(