To be fair, she doesn't seem to be making the effort to talk about it. If she isn't willing to go for couples counseling,(this is coming from a woman), it it time to separate if not divorce. She can't expect you to be happy for years on end in an affection-free relationship.

Cheating is a mess, you will lose so many people's respect--eventually your son's too (kids always find out eventually.) Divorce is hard on kids but not as hard as living with two people who hate each other.