A short, but painful apology letter to Mama. Say sorry to Mom and do the right thing.
Mom, I'm sorry for what I've done.
I didn't want to put you through this. But it was the only way out for me. I don't want you to get involved- you and Dad. Please know that this is not your fault and nothing you have done or said in the last twenty years of my life attributed to this. All I ever got from you was your unconditional love and I am grateful for that.
I'm sorry I hurt you terribly Mom. But I feel its about time I resolve things on my own. No matter how bad things are, please always know that I love you very, very much.