Hi, I'd like to help you with your question.
It sounds like your Mom has trouble with expressing her feelings. She also appears to have issues with anger and hurt.
When she says she is not mad, she may be partially correct. Though she does have anger issues, she also seems very hurt, possibly somewhere in her past. Was she abused as a child? I suspect she may have been and never learned to deal with those feelings. She did learn to take out how she feels on others and lay blame, with little logical reason to do so.
The problem for you is that in trying to get her to understand what she is doing is wrong, you are running up against her denial. She is pushing her feelings away, denying they are there and putting blame on other people so she doesn't have to be responsible or handle her feelings about the situation. Apparently, this works for her in some capacity and she will be reluctant to change it unless she has a very good reason. She did change how she was toward you after she married probably because she felt safe to do so and you became an adult, which often changes how abusers act towards their victims.
Simply put, your mom needs to see a therapist. She could work out whatever caused her to react the way she does and relearn how to handle her feelings. In order to have therapy be effective, she needs to want to get better. This is the tough part. Try talking with her again, maybe this time with her husband. Let her know you care and you want her to feel better. Tell her you want your relationship with her to improve. Her husband can add what he feels and see if she is willing to listen. You may not get anywhere at first, but keep trying. Offer to go with her if you feel comfortable doing that.
In the meanwhile, try not to react to what she says. Keep trying to talk with her but if she backs off give her space. She may see that you are not reacting to her and she may come around. Don't keep trying to figure out her motivations. Often, that is what she wants you to do. It becomes a game and feeds her needs. Just talk about general topics, ask how she is (but don't go further with it) and keep the conversation on lighter topics. If she won't talk with you, then shrug it off and talk with her husband. Don't talk about your mother with him but focus on other topics. She will see that her behavior is not rewarded and she will have to change.
If you find that your relationship with her is getting too much, consider therapy for yourself. Talk with your doctor for a referral or if you attend church, your pastor. You can also find a therapist at www.findatherapist.com.
I hope this has helped you,