I resent my mother. Is this wrong?

You really have a right to feel as you do. So many Mothers take the abuse from their husband because they think that they need to stay in the relationship in order to provide shelter and food for their children. They do not realize that they are actually harming their children, as you have been harmed. Try to realize that your Mother was a very brave woman and only stayed in the abusive situation because she had no other choice at the time.