You can't change anyone but yourself. If you went to therapy, you could learn to accept your mother as she is, realize she's never going to change, and discover effective ways to minimize contact. It sounds like you've been in this dysfunctional relationship for so long that you don't know how to extract yourself, but a professional can help. However, you've got to be motivated to do the work, take a hard look at yourself, and be willing to see things in a fresh way. What you're doing now is making you miserable so why not try something new?
Talking with your mother about this is a waste of breath. In fact, she probably loves the attention, the drama, and the attention on her. When she's abusive or starts to parentify you, leave the situation or end the phone call. Do this each and every time without fail. Eventually, if she truly wants to spend time with you, she'll stop the behavior. If she doesn't, you'll know that your presence doesn't mean much to her.
Our only power comes from changing ourselves. Yet, change is scary. The spiritual writer, Iyanla Vanzant, sums it up perfectly with these words: “There is no greater battle in life than the battle between the parts of you that want to be helped and the parts of you that are comfortable and content remaining broken.”