I am sad and depressed..i need my best friend..? major help..helpful answers appreciatedd!!?

have this best friend named mollyy and i love her to death but she is friends with this girl who i hate and it KILLLSS MEE! the fried is such a ***** and says all this mean stuff about me and i cry because she used to be my rlly good friend who i trusted. she so clingy to my best friend and always wants to take her away from me..and tht girl whos name is taylor tells molly how they are best friends and she can tell her anything..but molly always tells me how i am her best friend and she can tell me everything..she can't tell taylor anything..but she is so nice to taylor and she always treats me different...she believes since i am her best friend.. she doesn't need to take fb pics with me..or change her status messages or hug me..but she does tht with taylor..but it would be nice if she would take pics with me..i feel like she is embarrases with my social status because if we had a social ladder..i would be one step below her...her and tayor got in a fight like she was ignoring mollyy and she was upset and i helped molly..and when they made up i was sad..and like she ditched me on vc for taylor just because she felt bad about the fight..and i told her off and she got mad..and she doesn't get mad at taylor when she ignore her when they had plans to carpool together and my friend had to go by herself..i am kind of involved in the fight because taylor asked me and molly to hang out and we ditched her..she forgave mollyy but i dnt want to fight with her because i know she will say bad stuff about me and try to take molly away from me..i am just not in the mood to fight..also my other friends hung out behind my back when i asked them..also my friend cuts me out of photos...these boys called me fat..i didnt have plans on saturday and i felt like a loser..my friend invited me to go to hershey park but blew me off for my twin sister...i am just soo overwhelmed..i dnt want to go back to school..i feel so empty .. i cryed this morning because i hate my life and my social life..it reallly suckss! and today molly confronted me about everything bad about me and it was really mean and hurtful i cryed..she i usually go to her when i am upset..buut now she thinks i am a pathetic person who cries all the time.. when i need her the most she is being so nasty and such a *****..and she keeps yelling at me..i cnt trust anyone..im a huge mess andi am crying over the smallest things..life molly is saying im anoying sometimes which rlly hit home because i feel like i am being normal and she says tht we had the worst sleepover on saturday..idk wht hapened to her..is it me and my mood swings? she is like trying to make me jealous with taylor and i am sickk of everythingg!! btw i am in 8th grade