I want to live with my dad but mom won't let me?

I live in Texas and im 15 my parents have been divorced since i was 4 & ive lived with my mom since then. She won't let me live with him because he wasn't there for us when i was younger but the past 3 years he has been the best father imaginable. I got into a lot of trouble living with my mom and started hanging out with the wrong "crowd" or whatever so there home schooling me but i want to start over completely by moving to my dads so i know i wont fall back into old habits. I know moving in with my dad is what is best for me but my mom refuses to even let me tell her exactly why. Any suggestions? Thanks.