Relationship Advice . Help Please !!?

Okay so i have a boyfriend and we have been on and off for ten months now and he have cheated on me twice but I love him so much and I didn't want to lose him !! But its like now our relationship is draining me and when I tell him he keeps saying we can get past it and stuff . I want to be with him and everything but right now sometimes I feel like I want to be single and my BestFrnn is always there for me and I been knowing him since sixth grade . I'm in love with my BestFrnn and my boyfriend !! Yesterday me and my BestFrnn stayed on the phone for like six hours and talked about a lot of stuff and I'm so comfortable talking to him and everything ! Then when we got off the phone we start texting and we start admitting that we have feelings for each other and everything and that we love each other ! Problem is my boyfriend don't like him my BestFrnn ex gf don't want to let him go and he still love her and he loves me too so what am I to do ! My BestFrnn makes me feel special and he knows everything about me and my boyfriend I love him so much !! What am I to do ?