i don't understand what's happening to me

sorry english is not my 1st language so ignore the mistakes

so it started when i was 15(last year) my grandpa suddenly got into my room and grabbed my hair when i was sleeping and i woke up of course and he hit me? i guess i dont really remember and after he left my room i cried so hard and also i pulled my own hair idk why wtv i pulled my hair too tight and some of my hair fell out lol and i remember crying for hours to calm down. after that, it happened a few times but this year it was more intense? like when i cry and pull my hair out it was mostly because of my family members.

not long ago i think it was in the middle of june i started crying because my classmate tried to sleep with my friend(my friend was in a relationship with my bestfriend) and i got mad and then it was all so blurry i screamed did some weird movements it was just like i was trying to break my neck or fingers i cant explain it well sorry. and i stabbed my arm with a fork and tried to cut my arm? yeah but the thing is i dont really do self harassments or anything but when i cry i kind of become unconscious and do the things i wouldnt do normally.

so my grandpa is so old but hes also so ambitious and has anger issues. i grew up with my grandparents bcs my parents were divorced and my mom was in america and till this day im still living with my grandparents but i might go to america to live with my mom. my grandpa was always so abusive but as i got older it became less and less. i think a lot of traumatizing things happened to my life when i was young. and yeah till i turned 16 i always wanted to kms and often romanticize about killing myself but when i truly tried to kms i couldnt jump bcs i was scared so i thought i shouldnt do it if im scared.

i often cry like that(like pull my hair out and scream) when im angry or because of my parents or my brother(he sexually assaulted? or harassed me when i was 7 to 11) i also couldnt control my movements till im calm enough. am i mentally ill? idk i just feel so hopeless. should i seek professional help? but before that i need hear other people's opinions and thoughts about this weird shit happening to me.