It has to be enough that you know.
You know what happened during your marriage. You know the truth.
Anvil is right. You won't get him, or his family, to acknowledge that.
It will never happen.
I spent a lot of time trying to convince my AXH about the error of his ways and how his actions had hurt me and the children. None of it got through. None of it. He said he was sorry -- but it was "I'm sorry will you come back now?"... The only thing he was sorry about was the consequences his own actions had led to.
He needs the reality he has created to continue drinking. If he listened, or if his family listened, and really understood you, they would have to do things differently. And they don't want to.
So stop wasting your time on trying to get them to see your point of view. Alcoholics perfect the victim role. They don't want to share it.