Ahh I'm sorry that you are having so much trouble
When I was a teenager I was constantly getting sick with what were diagnosed as migraines but were more than likely sinus infections. When they finally did a scan they discovered that one of my sinuses had not developed fully. One quick surgery and I have NEVER had another migraine or sinus infection.
I hope that you do not need surgery like I did, but if they do find something that doesn't necessarily mean it's a bad thing!