Bff troubles ..............................…

i have a really good friend and she hurts me the other day a girl wouldnt give a cracker to her so my friend got pissed and started calling me a spoiled brat and hitting me in the sholder and she said shes pissed and needed to let off steam because she was under "pressure" from the school play also today it all starded in gym we have to dress in our uniform or we will get our grade lowerd so i was going to wear my black sweats which we are alowed to wear black sweats and i didnt have black sweats on it was cold so she demanded she would wear them even though she had black shorts you can wear also i needed them so i said no nicely and she gets all snotty and starts yelling at me and does this weird gesture where she lowers her top lip and starts punching me sooo let let her wear them then on the track she kept on punching me in the shoulder and i always tell her to stop but she never does so i dont like to hurt people so i tickle so i tickled her then she kicked me hard in the stomach shes done that once before and it hurts then she called me an idiot for not taking a joke because she said that she acedently did it.. seriously !! ugh and she has done many others rude things i cant even remember there is so many what should i say to her and what do you think of her