I'm 19 and really in need of some help. I used to play softball and run cross country and never had any sort of health problems. Since last summer though, I haven't been able to run at all.
I end up about to pass out before I even hit 1/4 of a mile. I can get plenty of air into my lungs, but it feels like none of the oxygen gets to my muscles or my brain. My tongue and my gums feel itchy and I can taste blood even though it's not in my saliva.
If I push myself further, I get this weird taste of ammonia, but not in my mouth, more like in my sinuses. My doctor said it's just a symptom of my sinusitis, but it's recent and I've been diagnosed with chronic sinusitis since I was 9.
After that, my vision will start to get really sharp and focused on weird things like blades of grass, then everything will go purple and I'll black out. Sometimes my hearing fades out too.
I don't know what could be causing this! My doctor was adamant that it was just due to the fact that my level of physical activity went down a lot since I stopped playing sports in high school, and I just have to work my way back up again. She also mentioned that I was probably overheated trying to push myself during the summer. But I don't think it should have been such a dramatic change, and it's winter now and I still have the same problem.
Does anyone have any idea what this could be, or at least what kind of problem it might be? I don't know if it's a respiratory thing or a cardiovascular problem or what.