I am so scared I have brain tumor.

Hi, I'm a 14 year old girl. I've had unexplainable dizziness (and other symptoms, like vision issues) for 4 months now 24/7, the only diagnosis I've gotten is cervical vertigo or PPPD. However today I fainted at school and now I'm convinced I have a brain tumor.

I'm so scared I have a tumor. I have an MRI of the brain scheduled in two weeks but I'm scared something is gonna happen before that. someone please help me. I need someone to talk to about this. please...