I Am Fit 19 Year Old Male And Lately When

I am fit 19 year old male and lately when working out even doing the slightest things i have trouble breathing and begin to gag and my eyes water. Even at home now i get hot my stomach feels queezy and i can't eat as much as i usually can. If i press around my stomach area i get the sensation of vomiting. Also when playing sports i feel sometimes that i may faint and begin to again gag and my eyes water. If you could please give me some sort of explanation i am begging to feel very worried for my health.