I think you should think of yourself, first.. because no one else will. If your mother is being/has been toxic and you don't want to have anything to do with her.. well, yeah, I'd say cut contacts. Especially because you mentioned she's doing just fine right now, so.. I don't see why you should feel guilty.

But this is just my opinion, and it must be YOUR choice - do whatever you think it's the best for yourself I'm really sorry that you had to put up with all of this... abusive parents can really destroy one person's life. Do what you think it's right, take care of yourself, and keep moving forward