@Starvinmarv - I'm so sorry for your situation. I agree with @DivorcedAndDelighted, an affair (if you could find someone) isn't the way to go.
Could you possibly discuss an open marriage? It doesn't work for everyone, but that way, it wouldn't be an afffair, because everyone knows.
I've posted this privately to someone else on the thread who reached out to me, but...
To those that feel trapped in a relationship, ask yourselves how much it has cost you in anger, resentment, wasted time and opportunity?
How long do you have left to live? Do you really want to spend it in a relationship that doesn't work?
Children are remarkably flexible and versitile - they will adapt. Money can be replaced (not easily, I accept that), plus, you can't take it with you, and no-one knows how long they have.
Maybe it's time to move on, and start living again.
Or we could book that hotel, and have a sexless marriage support group meeting! 