I can’t imagine going through anything like what you have, but thank you for your bravery in sharing and giving such an honest and painful perspective - I hope the writing does bring you some measure of healing.
It also makes me wonder what your mother went through as a child, as I want to believe that no one wakes up one day and decides to be a hateful bully of a parent for no particular reason. Not that her own past should be any excuse for her behaviour . Of course I don’t know her situation as you do, I can only imagine that she too must have been deeply lacking in any healthy example of motherhood.
May you be surrounded with love and healing relationships.