I know you live in a small town and it is such a shame you cannot join a group that does not have your mother in it. She sounds like a domineering person and you will look back with pride on the day you stood up to her!
Dont cave in to her controling "now I'm not talking to" behaviour either. You know that is just another way of trying to control you.
Nest time she tries it, why not laugh in her face? "Oh Mom you crack me up- look everyone! My mom still thinks she can tell me what to do and I am a grown woman! Do I look eighteen? Oh quick, bring me a mirror- We have great genes- we all look young in our family- isn't that right Mom? What a crack up" And walk away from her. She will never be done trying to control your life.