I wish I had not contacted him. It just got to me what my friend informed me of... I wasn't sleeping and I should have absolutely taken the route... when in doubt do nothing.
Again, I'm so sorry you're going through this.
If you haven't already, May's thread is a great read. She's dealt with a PA and her ex broke it off and seems on the reconciliation path. She simultaneously was clear divorce would not be a happy outcome, while putting up heroic amount of non-pressure and non-prying. In May's case they had younger kids. In your case you do not. It's worth considering there are many people who'd love to be your partner who aren't lying cheaters.
My ex was AMAZING. She taught at Harvard and was a world class athlete, she's an extreme adventurer.. EXCEPT she yelled at me, deceived me, wouldn't re-commit, and was triggered by my son. At some point, you realize those EXCEPTs outweigh the plusses. We were on the reconciliation path and I decided to finally step off it. I had a 2-month rebound after. I had a better time with someone who wasn't up to my ex physically or mentally, but was an honest person looking for commitment.
You said when in doubt do nothing. HE JUST TOLD YOU HE'S CHEATING ON YOU!!! Responding to his texts, helping him, promising to help later, apologizing so much he's asking you to stop..
Consider stop responding until you figure out what you want to do.