Reality check???

Okay, so I just went for a run... I was going to run the same route I've done before-run up to and down St.Louis street then run back, it's 3 miles. Well, about 100 feet into the run I felt like my legs literally weighed 90 lbs. My breath was really short and I was sweating PROFUSELY! I even made a wrong turn after like 1/2 a mile... as I was running up the big hill I couldn't help it, I had to stop! Seriously guys, I can't remember the last time I had to stop running like that! I started running again and ran the rest of the way home but I even shortened the route... I probably ran maybe 2 miles the whole time... I guess my body is just giving me a reality check that I can't eat whatever I want and then think I can run like usual. Granted, I did just eat a sandwich and some chips about an hour ago and it IS hotter outside but it's still no excuse for how bad of a run that was. I better whip my butt into shape if I think I'm going to finish the Turkey Trot in good time! After this run, I'm thinking I might have to bumb my goal from 27 minutes to 30 minutes for the trot!