Should I leave my 3 year relationship?

So my relationship has been having problems but nothing that cant be fixed...We are kind of long distance.We live 3 hours from eachother.Recently I found out he cheated on me from someone on a gaming chat app !(discord) they really only talked dirty and he sent one picture to her it hurt me but I was being SUPER mean to him at that time and not actung like a girlfriend so I dont really feel like he did it just to do it She lived in another country.I dont think hes ever done anything with anyone in person.He was my first kiss and We both lost our virginies to eachother.Even though it still hurts he appoligizes and says itll never happen again and well get better together.I talked to somoene else I had seen him once before through a family member but he was in a relationship at the time but hes been super sweet to me and seem alot more grown up amd mature but im afraid to leave the only person Ive ever relied on,trusted.I stopped going to school because I wanted to talk to him (I did this all on my own)I pushed everyone away because I thought hes all I needed but I do kind of feel I still love him more then he loves me hut hes always there for me and we said we'd never hive up on eachother and he told me his heart only beats for me...Should I leave...or stay...