how do i get over him even though i never dated him

hi, i (f17) was in a “situationship” or more so a talking stage for a solid 8 months on and off. i blocked him (m19) last month and didnt say anything because it was genuinely draining the life out of me. everyone around me could tell that i just wasn’t happy and it’s true i wasn’t. he was manipulative, mean, lustful and just evil towards me. while he did genuinely hurt me multiple times throughout the 8 months there were times that were just so so good and i wish i could go back to those times and relive them (like when we would randomly call and talk for hoursss about dumb stupid stuff).

but my problem is how do i get over him? he added me again shortly after i blocked him and it’s just sitting there in my requests, everyday im so tempted to add him back and i know i cant. almost everyday now ive been thinking about him and i cant go back for the life of me but i need to get over him and i dont know how. any help? please