Hi, for the past month or so I've been getting severely nauseous everyday for no reason. Every time I eat I get nauseous. I am 16 years old, I play sports (cross country running and rowing) so I am active. I don't feel fatigued or anything, just constantly nauseous and when I feel like it - I'll allow myself to vomit. What is wrong with me? I have a doctor's appointment next week.