Good luck with your appointment, id recommend making a list of things that have happened and how you’ve been feeling, this is so you can make sure you say everything important. Your gp might then refer you to camhs, but if you think it’s beneficial repeat a couple of times that you want to be referred and hopefully they will. Although, if you get referred to camhs your parents will know about it since they have to give consent etc. I was in the same situation a while ago so if you have any questions just ask