My husband cheated...I'm so confused?

I just recently discovered that my husband cheated on me once physically (no but still wrong) and emotionally for close to 6 months. We have been having major problems due to the fact that I felt something was wrong I just knew there was someone else that he was communicating with. I've spent the last 6 months with extreme anxiety, I've even gone to counseling, read books anything to help me with my anxiety that was all due to me thinking he was cheating on me...I asked him repeatedly to tell me if there was someone else to which would reply no and that I was being crazy and psycho for no reason..blah blah blah. This man has seen me become physically ill due to his possible affair but all along he was having an emotional affair which recently turned physical. I found several emails from him and his little friend last week and as you can imagine all hell broke lose I confronted him and her (she use to work with both of us we met at work) she's also married and has kids. She said they we're just friend that were confiding in each other since both were having problems in there marriage blah blah. I have kicked him out of the house and changed the locks but he called the police and they told me I could not kick him out until we were officially divorced. I honestly feel destroyed my entire world has been turned upside down. I really tried to believe it was all in my head but my gut knew something was wrong. The womens husband is also aware of the situation and has threaten to kill my husband if he ever tries to contact his wife again. So now my husband is crying saying he never meant for this to happen that our problems made him want to have a females perspective and that she was just someone to vent to and he never meant for it to turn physical and that it only happened once...to me once too many. I still love this man we have been together for over 6 yrs and married 3 and a half we have no children but were suppose to start trying for a family this year. I know that I am not a perfect person and that we were having some problems but I don't think I deserved what he did. I need advise...can couples really get thru something like this? Am I stupid for thinking it was a one time thing? am i setting myself up for a lifetime of heartache. I do want to add that my husband is a very caring man he's not just my husband but my best friend and has stood by my side thru some very difficult times...which is why this whole thing is so hard to process. I appreciate any advise or anyone who has gone thru something like this please let me know if there's hope.