Take @AttilaTheMeerkat good advice.
Your husband has badly let you down, and he needs to know it.
Loyalty in a marriage is very important.
You need to help yourself.
You can continue to allow your mother also abuse you, or you can step away.
Whilst you have ANY contact with either of them, you will be abused.
It really is that simple.
Her age is of no consequence.
She is abusive, just like your father.
Step away from them BOTH, if you wish to protect yourself.
Your husband needs to decide what is more important, helping out your abusers or being loyal to his wife.
Block their numbers and step away.
It sounds difficult but people do it all the time.
They are happy with the peace and calm their choice brings them.
The ball is in your court.
Personally I see no point in remaining married to a person who isn't loyal to you.