I want to be more independent from my mother
Why do you want to be more independent from your mom?
I want to enjoy my life with my girlfriend more instead of spending time with my mom.
It's good to go out and be independent and establish your own life. I agree with your decision.
Too bad what she thinks. I'm going to do what I want anyways.
You should be able to.   Make sure that you establish your boundaries and are respectful of others while doing that.