hi, i'm a 17 as well in grade 12
though i have no medical advice for you i thought it might be good for you to know that someone out there in the wide web cares. if you say you're getting EKG's, MRI's, CT Scans then just stay strong, let your family and friends support you and let the doctors do their job. i cant say that i understand what you're going through having never being in that situation (and its really annoying when people saw they understand when they dont) but i hope the best for you, stay strong.