My mum wont accept my appearance? I'm trapped in the house?

Well, if you've tried everything and nothing seems to be working, you are 18 years old and you've finished high school. you can always move out seeing as your now legally an adult. if you don't have any plans to go to college, try getting a job. she cant force you to stay in the house anymore. I suggest looking for a job and moving out but everything has their ups and downs. In the end its your decision on what to do in your life.