Husband cheating, I busted him! What should I do? Should I believe him? Give it another try?

I found out my husband has been having an affair! thru phone records he talked to this girl NUMEROUS times a day and was also staying with "friends" while out of town and SWEARS no sex was ever involved. He sd he was trying to stop it before I found out cus it got out of hand it was just "emotional" I am a Christian and I WANT to believe him but...?? I made him call her to break it off and he called ANOTHER FRIEND (girl) to make it look like he did, then of course I busted him on that and called the girl at work and confronted her, he stated she called and broke it off but I do not know if this is another lie!!! We have been going to counseling at church and I still feel like he is lying even to the Pastor. He SAYS he loves me and wants our marriage to work but will not confess all his sins (at least that is how I feel). I think he still has contact but he swears I nailed the door shut...but why did I have to nail it? or did I? Should I call her again to find out or what? Should I stay in my marriage? Not sure what to do here. I have prayed and prayed but still sick at my stomach and always a wreck when he leaves. HELP!