Yep....been there. Especially the CL thing. Those ads are so provocative.
First, I think it is good you feel remorse and are contrite and want to be a better man. Cudos to you on that. Second, please don't mistake the fact that you didn't engage in oral or intercouse to mean you didn't have sex with those women. A woman other than your GF was giving you a handjob.....that's sex. If you doubt me, ask your GF...or any girl for that matter. Okay?
For some practical advice, let me offer you this:
What you need is some impulse control skills and perspective imho. You get all excited and flustered by looking and dreaming of this activity...let alone engaging in it. Consider this Stage 1 thinking. The trick is not to stay in Stage 1 thinking. Listen, we cannot control impulse thoughts; but we can control our behavior and our entertaining of those thoughts. My priest once said, "You cannot control the birds flying overhead, but you don't have to invite them to nest on your head." See the point?
How do you stop that? By realizing you're in Stage 1 thinking and move on to Stage 2 thinking. Stage 2 thinking is thinking about the consequences of your potential thoughts and actions. It is thinking of how crappy you feel right after this acting out. The guilt and shame. It also thinks of how hurt your GF would be if she found out; how devastated she would be. Like when she found your web history. Remember her face? How 'fallen' she looked and upset she became? Do you want her to feel like that? Do you want to be that kind of guy who makes her - someone you care very deeply about - feel like that?
The trick is to slide right past Stage 1 thinking - because you cannot control that impulse thought - right into Stage 2 thinking. This will help stop you from lingering on those thoughts and letting those thoughts propel you into behavior you know is wrong and doesn't contribute to your long term happiness. Okay?
The goods news is that you are catching this earlier than most. Now is the time to nip this. I think you're very noble for wanting to be an honorable man. This is a battle...and often a daily battle...but it gets easier if you develop a skill set. Stop the behavior that leads to acting out. That starts with your eyes. Only use the puter when she is home; have a filter on it that eliminates CL and those sites. Use a progrmam that sends your history to your GF (yikes!).
You're not a freak, weird of a perv. You're a guy, human...but you don't have to give in to your lesser self. There is an internal conflict with moral men: The male in all of us want to look; the man inside many of us don't because we want to be better, honorable men. This kind of nobility is work because we are fighting our nature. But it is worth fighting because we have values and principles.
Good luck Sir and I will say a prayer for you.