Oh boy..boy..it is clear that you still have tons of unresolved anger and resentment toward your mother. Better get working on the forgiveness process. From that point and on, maybe...just maybe...you can mend and restore your broken relationship with your mother. Why not be the bigger man here?
I would hope that your heart isn't made out of granite.
Here is the thing...
I have parents who were both WASes and engaged in affairs on both sides. Divorces, acrimonious times, and alll that. I look at them as humans who tried THEIR best at that time and their past actions didn't lessen my love for them at all. Yeah, they sure could have handled certain things differently. They know that I have complete unconditional love for them.
Why? Because I forgive them for their stupid actions.