I dont know what to do. im scared?

im in highschool just saying. so i went out with this guy for 6 months(his longest relationship by far) and i was happy most of the time and after we broke up i started noticing things. My friends pointed out that instead of calling me a cute name like baby or something he'd call me ho or b*tch and when i asked him about it he would say its ok because i love you and i believed him. he would also do other things and tell me its ok because he loves me. a week before we broke up he started doing tons of drugs. it was really scary because he would call me when he was high and yell at me. after he broke up with me(because i told him he had a drug problem) i still tried to help him but he would only tell me that everyone hates me and thinks im annoying and ugly and cuss me out alot. after he does this he would tell me he still loves me. a while later i went to a party and all of the people there came up and told me that he had been telling them that i do things i would never do (like have sex with him and doing heavy drugs and drinking.) when i tried to confront him about it he started screaming at me and yelling. after i left the party he called me high and told me i was a useless b*tch and no other guy would want such a filthy ho. i got really scared and went on my facebook for backup. then i had seen he kept sending me terrible and explicit messages nonstop from 9 at night to 3 in the morning. i called some of his friends to calm him down but he wouldnt. some of my friends contacted his mom and told her he was harasing me and that he has been doing drugs. she called me the next day to see if it was true and i said it was. she gave him a drug test and it came back negative. now she thinks im lieing and is reallllly mad at me and thinks im getting everyone to make up rumors about him because he broke up with me. my ex then emailed me to tell me that spice(the drug he does the most) is not detectable on home drug tests. idk what to do. i can ignore him but im going to see him at school. im really scared of him. what should i do? and dont say tell your parents. they dont care. i dont have a school counselor now. am i a bad person? idk what to do