How do you cope when your mother doesn't love you?

My father died when I was 9. My 4 sisters and I were left with a mother who didn’t care about any of us. I was the youngest at home. My sisters all moved out as soon as they could and got married. My mother was the oldest of 12 children herself. Her siblings all thought we were horrible children and we were to blame for not getting along with our mother. They didn’t understand that it was HER that didn’t want anything to do with us. They were all wonderful parents themselves and couldn’t fathom having a sibling that was unloving towards her own children. They always tried to push us on her and we kept getting rejected over and over again. I am now 54 and I finally hit the last straw with my mother. My only child, who I am extremely close to, just got her doctorates in physical therapy and is getting married in less than 2 weeks. I was not going to invite my mother as she hasn’t had any real contact with me or my daughter through the years. Her sisters guilted me into inviting her, so I did. She RSVPd months ago that she was coming. Yesterday she called me and gave me all kinds of lame excuses as to why she now can’t come. I’m done. No more. I will never speak to her again.