Soooooo confussseeeddd !!! pleeease help !!!?

ok so this girl i know hates me. i dont not have a clue why but she just does ! so first off i was texting my friend meredith and then the girl that doesnt like me, Katie, started texting me on merediths fone . katie was saying " i hate you, you walk around like your the **** and your not your onlyin seventh grade" so first off im jsut like !:?!?!??!?!? your such a freeeaking hipocrate! cuz she walks round like shes the **** . but all i responded was "ok" so anyway later on i guess katie found out i am best friends with her good friend Lexi and lexi offered to tell katie to back off of me but i told her not to. SO i thought everything was all good until i was on the bus and listening to music when i sware i heard katie yell at me saying "your ugly!!!" and i jsut ignored the ugly *** ***** but then i saw that she threw something at me. i assumed it was ppaper and when my bus stop came i just walked off like nothing happend. until later on i found a piece of GUM ALL UP IN MY HAIR. mhm yea in my hair. this pissed me off and it still does obiously cuz it was only two or three hours ago that this gum thing occured. So i got the gum out easily cuz my hair dresser said olive oil and peanut butter help get gum out (who knew ha) so now im just kindof worried that this whold situation will get around and ill be a laughing stock. but i mean idk why she doesnt like me, and i mean alot of people like me and thats why i cant handle one person not liking me.. i know im crazy. not everyone will like me but idk what to do should i pretend like nothing hppend and there was never any gum in my hair or what ? oh and now my mom is going to talk to either the parents of katie or the school andim like NOOOOO uggghhh help !!! oh and not many people like katie and if they are her friend they hate her behind her back and i honestly do not feel bad