Running on empty

I went for my long run last week on Sunday. I ran 14 miles. It was brutal! Mile 10, 11, and 12 were especially painful as they were on a stretch that has a crazy steep hill. Let's just say that when I drive up this hill I have to floor it to maintain 50 MPH. It's steep and long. But by the time I got there I was already tired and that hill looked like Mt. Everest. I think I walked a good portion of those 2 or 3 miles. I tried running, but it was only coming in short spurts and it was hot and all I had was warm water to drink that I got from an outdoor water fountain at the park. But I made it and then finished with a strong final 2 miles (mostly flat). I am excited about this weekend run, because I honestly felt great for the first 9 miles, and this weeks run is 9 miles I believe. I do have to focus on today's 4 mile run and tomorrows 7 miles at my "race pace." And then I have another 4 miles on Thursday. Here is a graph from the 14 mile run showing the elevation change, I got this from my cool GPS running device that provides so much cool and useful information!
The numbers are hard to read but on the horizontal axis you'll see the distance by miles. The vertical axis has elevation The hill starts at 4,260 ft and peaks at 4,470, which if I can add, multiply, divide, and estimate closely gives me a 2.25% grade over 1.75 miles. STEEP! Just for reference that is one foot of elevation gain every 44 feet, and the "big hill" in my marathon is 1 foot elevation gain every 66 feet.