Im a 15 year old girl and my dad still chooses my haircut. he want to chop off all my hair what do I do!!?

I am 15 and a girl and have long hair right now. it goes to my mid back and does have a ton of split ends. I straighten my hair everyday without a heat Protectant so I have split ends that go up to my shoulder. my dad insists on choosing my haircuts. if refuse or do something else, I get in huge trouble. he also chooses where I get my haircut at. he takes me to some place to Xanadu to some weird guy. he always shakes and it makes me nervous when he cuts my hair. the salon is kinda a cheap place so that makes me nervous too. right now my dad is saying that he is sick of my long hair and all the split ends so he is scheduling an appointment for next Friday evening. he said that he is going to tell him to cut it up to my chin in a bob because my hair is so bad. that's about 8 or 9 inches off my hair and im terrified. I hate having my dad choose my haircuts but I dink know what to do because im to scared to say anything. what do I do!! should I just go through the haircut? please help!