Stay with a cheater or leave?

So 2 months ago I caught my fiance cheating on me 2 mon away from our wedding (july 4th). He swears he never touched her. Just went to a bar once and hung out a few times outside of work. He swears they only talked and had a few sexual talks. He. Talked to this girl for a month in half behind my back. Lied to me when I questioned. We had many arguments. So here im am still living with the guy and counting the days until july 4th arrives and ill be a big mess. Since the whole cheating thing occured he has become the guy I fell in love with. He swears he will never take me for granted, cheat on me, and. He will make it up to me.... im so confused do I stay or leave? I love him so much but I can't get past all the lies it eats me inside and since he lied I don't know if I believe him when he says I never touched her...help