Update... we were together 18 mnths, I have a child, she has 2. Neither have ever introduced anyone to our kids before and we met through work

I love this girl move than I thought possible

Honestly, I think nothing or very little of what you wrote contributed to this break up. I think once she moved and got closer, she saw the real you, not the façade you were able to keep from a distance. Once she found out you were not what you advertised she moved on and back.

As far as moving on for you, your mom (mum if you insist) she means well but she isn't going to help you move forward with her methods. You are best to go NC all the way, and that should be easy since she's moved back home. Now is the time to focus on yourself.