Is he planning to cheat or is he planning to leave for good?

I suspect my husband is up to no good. I saw web history and emails where he writes to women that he is looking for a new wife, lied that he is separated or divorced. He has been very cold to me lately too, and refused to touch me. I confronted him about the mails and he quickly deleted everything and claimed he didn't do anything. He said I should file a divorce if I am not happy wih him anymore. I don't know what to do. Is he plannng to cheat or leave me for good? This isn't the first time I caught him doing this, but in the earlier time, he was still intimate but now he isn't. My friend said I should wait a while to see how this whole thing unfolds, but it is extremely hard for me living with someone who isn't showing interest and is "looking for new wife" as he claims in his mails. Please advice.