Oh goodness can I relate to this.
It was my husband's affair (initiated after a drunken Octoberfest) that helped snap my head back on straight from my marriage and his use of alcohol for his marriage.
For some reason this hurt got me into Al-anon and directly facing myself in a way that nothing prior to it had done (there is a saying about when it hurts enough).
I read a lot of books about both, attended a lot of Al-anon (and Open AA as appropriate), started and finished the divorce process and continued my own recovery work.
I am rounding out a year from where the whole divorce process began....learning about the grief cycle has helped too.
It is easier now, I have more good days than bad.
Take care of you, and sending warm thoughts your way.