First of all, I am so sorry about what happened to you. That’s one of the worst things to go through, and I can only imagine what you’re feeling.
I’ve cut ties with my whole family before due to various reasons, and it honestly made me feel a lot better. I didn’t feel any pressure to constantly text/call them like they wanted, and I just felt free.
If you’re serious about it, I would suggest blocking them on Facebook (if you have one) and changing your phone number. It seems extreme, but that’s what worked for me. Also keep in mind that, if you have other family with whom your mom is close, she may use them to get to you. My mom did that; she used my brother (who I didn’t remove from Facebook) to see what I was doing, and I ultimately had to block him, too.
It’s not a bad thing, just be sure that this is what you want before you do it. I’m rooting for you!