Ignore the above comment.
Sounds like an anxiety
attack, or just too much caffeine given that you are only 17. However, if your pulse is fast, you feel like you are going to faint, getting short of breath (like you say you are experiencing), a trip to the doctor or ER might not be a bad idea. You could have diabetes
,SVT, atrial fibrillation
(doubtful) or maybe even an allergic reaction
to something you came in contact with. Without knowing a lot of other info (vitals, medical history, family history, recent exposures, glucose check....) we cannot say for sure.
I'd get checked out really soon (tonight!) to be safe.