I'm so sorry that you are hurting right now. I know you feel guilty for "spying" on him, but try to keep your guilt in perspective....if he wasn't giving you reason to be suspicious and was being up front with you, in short....not lying to you, you wouldn't have had to do this. You deserve to know the truth, if he won't tell it to you then you have to find out what it is on your own so you have the knowledge to deal with the issues at hand.
I can only imagine how hard it was for you to keep your cool this morning...I'm not so sure I could have done the same, see I'm not that strong. I can guarantee you though, if he is chatting, or e-mailing anyone off of that computer....that software will tell you, you will be able to read it all.
I'm glad for you though that so far you haven't found that he actually has an account somewhere; I'm praying for you that you don't find that he does have one because that adds a whole new level of pain. Right now....as far as you know he's just looking. What that tells me though is that he does have this "fantasy" in his head, he may be thinking that fantasy will disgust you. I truly believe my H thought/thinks that what he wanted or what turned him on would really disgust/repel me.....when really it's what I wanted all along too. Even though I was telling him this for years....he still didn't believe me.
Don't despair here Nicky, this doesn't mean your H doesn't love you. It does mean though that there's some BIG stuff to address and work though. I don't know if you downloaded just the free software demo or if you downloaded the full version or not....but the full version will allow you to capture screen shots at intervals, and have the log e-mailed to you at work (that's what I'm doing for peace of mind while we're apart) as well. That just might come in handy for you when you do confront him.
I found that when I confronted my H with a handful of about 20 pgs of proof....he didn't try to squirm out of the truth, it was so obvious I knew what he had been doing. I also printed out the keystroker log (minus the part where my login showed up)....so he could see exactly what I was able to see.
FWIW....I think you are wise to try to wait for a few days to gather more info. IMPO, a few days will show you that he is either simply viewing this stuff....or that there is more.
Nicky....if you want to please feel free to e-mail me at anitam@nordam.com to talk about this. I'll support you in any way I can....as will the good folks here.