I don't want to take my son to visit my mom anymore
Why don't you want him visiting your mother?
Because I don't like how she treats him.
Your mom loves your child. You shouldn't keep them apart like that. They are family.
It's just that my mom always yells at my son. I can't stand it anymore.
It's understandable why you wouldn't like that, but perhaps you should just talk to your mother about it instead?