I'm a sophomore distance runner from Virginia. Freshman year I fan 9:42 (3200) and 4:35 (1600). It was a really successful season and I'd obviously feel bad after races, but it was the usual feeling after a race and it subsided pretty quickly. This past cross country season (sophomore) my first race I started to feel really bad with a half mile to go, and I hardly got to the line because I was stumbling and couldn't keep my self up. I fell at the line and after I got up I was light headed and it was really hard for me to stand up without leaning against something with my head down. I ended up puking about 30 minutes after and felt better 15ish minutes after that. I had a similar incident (probably worse, considering it was my worst time of the season) at conference xc championships which ended my season and ultimately led to me getting an implantable heart monitor at the recommendation of cardiologists. I eventually got cleared to race again and had an okay season but it was frustrating because I couldn't get my two mile under 9:50 and I felt I should've been running much faster. Today I had another 3200 race and I was basically on PR pace at 800 to go (8:17) after a slow start. 600 to go I started to really crash, feeling similar to the previous incidents. My last 400 was horrible (I ran it in 84 seconds whereas I was popping 71s in the middle of the race). Again I had trouble even getting to the finish line and stumbled the last 150. I ended up running 957 which was disappointing. Again I only wanted to lay down. Eventually I threw up a lot even though I only had a banana as it was an early morning race. Felt better not long after puking. The doctors checked the transmission from my monitor and there were no scary heart rhythms so that rules out that. Everyone said I was very white/grey in all of these incidents. I gave it my all and stayed tough in each race. Can any of you imagine what this could be/have any tips?