I have been exactly where you are.
For me, it wasn't caused by the lack of sex in my marriage, it was a knee jerk reaction to finding out that my ExH had been messing around with other women for our whole 20 year relationship.
The whole time, I had been faithful. But in the aftermath of finding out that he hadn't, I kissed another guy in a club and it massively snowballed into having affairs.
Your comment about never finding peace, struck a chord with me. You won't EVER find peace whilst you are doing this. You know you might get caught. And the men are using your body for their own gratification. They don't love you. They may not even like you. You know this, deep down. So of course you won't find peace. The sex isn't good, because you have no real emotional connection. And men who have affairs (ime) are quite selfish in bed (and out).
I have now found peace. I left ExH and started dating again. I am now married to the most lovely, kind, handsome man, and honestly I would not ever consider being unfaithful to him. Not for a million quid! THIS is how you find peace. Leave your Husband and start again, would be my advice.
I'm guessing you met him quite young and didn't have many sexual partners before him? That was my case, which made other men even more exciting. Sadly, the men who have affairs are really the bottom feeders, so you are exposing yourself to the scum of society. You'll never find peace with that lot.