Quick background for my eventual answer, my "parents" put me on a street curb the day after my 18th birthday, back in 1974, drove away and I never heard from them again, 100% their choice on everything.
At first, it was tough as hell, BUT it taught me to look out for myself and to be careful about relationships and the strings that might come with it.
With the prior said, if I was you, I would RUN and never look back. In my 70 years, I have rarely seen a zebra change its stripes, like never, and if a human, especially a close one, was terrible and then down the road of life wants to "reconnect", RUN!
NOW, someday, sometime, somewhere, ON YOUR TERMS PERIOD, if you want to try to reconnect to any degree, make DARN SURE, that it is on your terms and meet in a neutral location, like a coffeehouse. As time moves on after the first encounter then decide, ON YOUR TERMS, where YOU and your mom want it to go forward with.
My "parents" never reached out and even in their wills it was stated that they DID NOT want me anywhere near their wakes or funerals, fine by me.
I made a great life on my own, and I NEVER EVER had to endure putting up with mind games or anything else.
Please be careful, go with your mind then your heart and do not get burned, no matter what the blood line is, NOT WORTH IT, in headache and heartache ever.
Hugs and sunny days to you!
Walter