My parents had a horrible marriage, but my mother stayed "for the sake of the kids".
The fighting created chaos in our house and my brother and I suffered from it.
I would hear my parents fighting at 1 am and would go into panic mode. I would always put myself in the middle physically, to protect my mom. The fights were never physical, but I still felt the need to be in the middle.
Staying in a bad marriage affects everyone in the family, especially the children.
How many times can you try with your wife?
You have a chance at happiness and I say "grab it", you don't want to end up a bitter old man. Your wife is not going to change, she will always revert back to her old self.
You have a right to be happy, remember we only go around once!
This is only my opinion from past experiences. I divorced my first husband and found happiness with my current husband. I thank God everyday, I made the decision to leave husband #1. He's now on his third wife, some people just can't change.