triathlon mental preparation racing training DNF hank Augusta 70.3

This past weekend at the Augusta 70.3, I did not finish (again). I had a descent swim and I felt very controlled on the bike with my efforts. I was excited to get off and run the way that I normally do (around a 1:20 half marathon). I took the first 2 miles very conservative and was able to work out some tightness in my left quad. Around the 3 mile mark, I began to feel into my normal running rhythm. As I made it through an aid station and took off down one of the many long straightaways on the course, I began to hav a major shortness of breath.