<human>: I'm just finishing up my first year in college, and I'm trying to get back into running. I was a decent track runner in high school (2:08 800m, 5:04 mile) so I'm confident with training techniques, form, recovery, etc., but I feel like something just isn't ticking.

Even in high school, I definitely feel as if I never reached my full potential. I give a lot of the credit to my times in high school to my natural physique (I'm 6'3, 155 pounds of lean muscle). I always struggled to find motivation while running; as soon as I started to get into difficult areas of a workout I would slow down severely. Occasionally I would have a great day, impressing my coaches and renewing their faith that I could become a real threat to our district competition, but I never really came through. 

More specifically, my main enemy is the heat. I swear, anything over 80 degrees and 2 miles into a run my head will feel like it's throbbing and my form suffers tremendously. I'm always sure to hydrate adequately, but I would say I sweat maybe 20% as much as the average person. I'm afraid I've tried everything to alleviate my issues, but nothing has really worked.

I love running, and I never plan on giving it up completely, but I do get discouraged when I think about how much more successful I could be. Do any of my fellow runners have any advice for getting over mental blocks? Or even just some advice about dealing with the heat.

Could you distill the essence of the text into 1-3 sentences?
<bot>: Feel like I'm not running to my potential, having troubles with mental strength, also have major issues with running in the heat.