We stopped fighting in front of our kids many years back. I vowed to live parallel lives until kids are off to college.....until my 13 year old son asked me why I married his dad in the first place because I we both. never looked happy. I received the strength from my children to divorce. I think kids who grow up with unhappy parents will ALSO need therapy to deal with the effects of a dysfunctional family.
Deciding to end the marriage or stay in it is a personal one and tough for people on the outside to make judgments or give free advice.