From personal experience, I felt quite similar to you, Stung. Now, I would have never cheated on my now ex husband, or any other man, but we lost our spark long time ago, he was very mean to me, and he said a couple of things that became an absolute sexual turn-off. What I did was day dreaming, asking myself, how would it feel with a "normal" guy? What would our evenings be like? And I started noticing "hunks," never talked to them, never even said hi, but I was noticing other men. Period. And that was telling me where my emotions were. I acknowledged these feelings, I was honest to myself. So there was the last nail in the coffin.
But tell you what, after divorce, I do not ask these questions anymore. When I was in a relationship, I wondered what a normal one would look like, but it did not mean I was to look for a relationship in some kind of a dating frenzy. At the moment, I do not want a man, I do not feel like dating, and I simply do not feel like going through the process. I'm tired, I'm drained. This marriage pretty much drained life out of me. And there is still so much crap to clean after my ex, debts to pay, reestablish old connections.
Just trying to say that what you are feeling is quite natural. But it does not have to mean that you really want to look for another guy or date. It may only mean that you are not getting what you want, and deserve, and perhaps are ready for a change.