I did a ride in Corpus Christi, TX, a number of years ago and got three flats. It was super frustrating; I think I finished a couple hours after the rest of the group. Ugh. There was a ton of debris on the road, plus back then I wasn't as vigilant about making sure my tires were properly inflated. (A bonus: while repairing the last flat on that ride, I laid my gloves down on the ground -- in a fire ant hill! I didn't realize it until I pulled them back on and the ants started biting me. Yeah, probably the least fun I've ever had on a ride....)

Now I check my tire pressure before every long ride, and at least a couple times a week for my regular commute. That, along with the kevlar bead in my tires, has solved any flat problems for me.

Your sleepiness and breathing problems say "allergies" to me. The same thing happens to me after I exert myself especially hard. Plus a whopper headache. However, I recently went to an ear, nose and throat doctor and he prescribed Flo-nase and azelastine. Since I began using them, I am amazed at how much better I feel -- I have tons more energy, and feel like I can breathe so much better. I'm kicking myself for not seeing a doctor sooner; I had no idea I could feel this good! So I would suggest seeing a doctor about allergies.