I don't see it as cheating because you aren't acting upn it. I am not married, but I can TOTALLY relate to what you're saying. It can be hard, because I found what my current relationship is lacking in another guy. That sounds so wrong, and as I type it I feel ashamed. But I took a step back, viewed the situation, and I decided there was so much that I love about my fiance, I would NEVER jeopardize that at all. So, the other guy was a co worker, so I had to switch jobs. I spaced myself from him because I knew that it was a bad situation.
Good luck, and don't feel down about it. So you're human, that's not so bad, right?!?!