Hi Tammy;
I'm so sorry to hear your plight. The reason your mother has apparently chosen the Borg over you, is because the JWs twist the scriptures and they always use the one where Jesus said "anyone who puts father or mother or brother or sister ahead of me is not worthy of me."
In other words, they have your mother convinced that if she associates with you, and puts you ahead of THEM, then she'll die at the Big A.
I'm sure you mother does still loves you and probably thinks about you every day. Perhaps you could suggest a relationship whereby you don't talk about the religion, see if she's receptive to that at all.
Take Care