How wrong would it be to tell my mother I don't love her?
Yikes, is there a reason you want to tell her you don't love her?
She's ruined countless lives and imprisoned people
Even though you may dislike what your mother has done in the past, it's wrong to tell her that you don't love her since family should always try to stick together and support each other. Even if your mother has done things in her past that you regret knowing that she did, you should still try to love her and maintain a relationship. People can change for the better and it's important to be supportive of your mother and love her so that change has a better chance of occurring.
F**k her, who says I have to love anyone?
Telling her you don't love her isn't going to change what she's done. Telling her you do love her but she needs to change might make things better.