Is my husband lying or am I an annoying psycho like he thinks?

My husband works construction remodeling hotels out of town usually. Sometimes I get to go visit other times he is there 2-3 months by himself. He got back from one trip after the birth of our child (he didn't come home for it because he said he couldn't leave). A few years later his best friend who also worked that job confessed to me that my husband was having an affair with a housekeeper at the hotel who also worked at a mcdonalds and he bought this girl a laptop. Considering they are best friends I believed the friend not my husband. I even emailed the girl because I found her on his Skype and Facebook. She confirmed it all to me and said she didn't know he was married. Now my husband says he didn't split the profit from that job with his best friend and his best friend was lying to mess him and me up and he was in cahoots with that chick. (2 years later they mess with us? doesn't make sense to wait to me). But then I discovered through my husbands computer that he had a secret email account opened with that girl as his only contact. I hacked in because her name was the answer to the secret questions to get into the account. Even more damning evidence I think. Then he says he only knew her 3 days before he left that job and he told her he was married and about to have a kid. He said he saw her at mcdonalds and commented how hard she worked at both jobs and she gave him her number. He told her later that while she was attractive he was married and it was nothing against her. But he felt bad for her since she was from Moldava and had no way to talk to her family so he and 2 other guys bought her the laptop not him alone. And then when asked about the secret email he said she set it up because she wouldnt take no for an answer and wanted to stay in contact but he never used it (which was a lie because I saw his history). Plus I am wondering why in 3 days he was around her enough for her to know his full name, birthdate, and address in order to set up the email account profile. If she did it. Now I don't buy his story and his version. He says his friend is just trying to get even for the money thing and he guesses the girl is helping. But she sent him an email after I confronted him saying I hate you and everything I have done I didnt know you were married and I never wanted to break up a family. He swears his innocence.....but I can't help but not believe him. Too much evidence. I am not stupid. But he has me doubting myself because he is a good manipulator and he tells me I am jealous, phsycho and annoying because i can't let this go. He refuses to take a lie detector to prove his innocence because he says I should believe him. Plus he doesnt care to prove it to me. I asked him if he doesnt care that I am hurting over this and suffering and I feel at a stand still in my life. He replied he doesn't care anymore or not anymore so I am guessing he did at one time. Should I go see a shrink because I am psycho and jealous. Because I really don't think I am. Thanks to anyone who reads all my story and responds because I have no one to talk to.........