You fiance, dad of ur unborn baby denies feelings for female co worker, he gets busted it was never physical?

basically they just talked about, sad thing is we all worked together, he no is employed else where now and our baby is 2 mts old, but I cant get over it, I thought something was going on and asked him he would tell me I was crazy then one slip on the computer (swear I didnt mean to find it,) but his IMs to her and hers to him got saved on recieved files. They said things like were meant to be together, your the most beautiful women I ever seen, he apparently made a comment about gotta luv me he said j/k she said you never know, he made a comment bout Leaving for his new job a few hours early so they could hook up. He admitted it all when I confronted him with a print out, and even though nothing happened and he works in the coal mines now and comes straight home I still cant stop thinking bout it. It sickens me. It was never more than an Idea in there heads but I almost feel the emotional relationship hurts me more than if it would merely have been physical, help me get over it.