Help

Hi idk how this works but I need help, so me and my bf were drinking and as a joke I said you can't get anyone else better then me, he then said to me wanna bet but I don't like her cause she to young for me... So I shouldn't have done it but I looked through his phone... I remember there was this girl that just turned 21 he got invited to her birthday party so I went through there old messages together I could tell he like her..... so my noise *** went to search her on FB on his phone and what do I see she already in the recent search bar, I feel like it's bitting me in the butt cause we used to go out back in high school but I was so young and dumb I cheated on him so for like 9 years I was single and so was he, he never went with any body else but me we been together for a year and a bit now I just don't know what to do I told him what I saw I asked him does he still like her he said no what am I supposed to believe they work together even though he say he never talk to her or see her at work but I don't trust him he's lie to me so many times am I just being a hypocrite? I really wanna leave but then I don't cause idk what he would do to himself I need some advice I hope this made sense lol