I'm sorry your mom was so mean to you. I have kids, and I can't imagine what it would take to call my own child ugly. Like my brain blocks it, I literally can't. What a mean person she must have been.
I hope you get to unlearn it. Please ask yourself why you wouldn't do it to someone else and why those reasons don't apply to you, because from where I'm standing this looks like it could be self-harming behavior.
