HIM Veteran Assistance Needed Please

Ok... I'll try to make this short, but I need to paint a picture of my miserable training day in hopes that my BT brothers and sisters can help me out.

I've been training for my first HIM on 9/7 (Prairieman). My training has gone really well all things considered. I've been using the Oly to HIM intermediate plan, and have kept up with it realitively well. With the exception of falling short a few minutes on swimming every few weeks. My long runs have been from 10-15 miles and my long rides have been from 50-80 miles. So I have no problem making the distance for each leg.

My training plan had me do a bike-run long brick 2 weeks ago and today. The first brick went ok but I took in too much nutrition on the bike, so my stomach started to bug me at mile 8 on the run. Today's brick was a total mess...

I completed 57 miles on the bike feeling pretty strong. I took along my two bottles of diluted accelerade (~100 cals each), 1 bottle of water,  4 Gus and a clif bar. Here's the order of the nutrition with accelerade for the first 2 hours:

:45 Gu

1:30 Gu

2:00 Clif bar

At hour 2 I went home to refill my accelerade and water, but the wife and kids were gone and locked the door. So I had to refill using the hose outside and didn't get another bottle of accelerade. So here's the last hour with just water:

2:15 Gu

3:00 Gu

I changed clothes for the run, grabbed 3 Gus, 2 bottles of gatorade and a bottle of water for an anticipated ~13 mile run (stash the bottles in a bush fo my 2 mile loop). It was about 91 degrees outside and I had very little shade, so the heat was a big factor.

After the first 2 miles I knew something was off. My legs felt heavy and I just couldn't move very fast at all. I drank some gatorade and sprayed down with some cold water and went on my way. At the end of mile 4 it really kicked in, and for the first time in years I had to stop and walk. I kept the bottle of water with me for the next 2 miles to keep drenching my head, but I felt like I was carrying a 50 pound backpack. I proceeded to walk mainly the last 2 miles with an attempt to jog for about 20 feet every once in a while. So I only "completed" 6 miles...

I got home and was spent. I took a shower right away, but I was shaking and felt like I was going to pass out in the shower. To the point where I had to sit down for a second. This has never happened to me. 

So now I'm extremely nervous that I won't even be able to complete my HIM next week. I don't think it was dehydration because I had plenty to drink. I think the heat was a factor, but I was still sweating and didn't get the chills or anything. I'm thinking that it may have to do with my nutrition. Looking back at my calories, I was probably taking in a max of 200 per hour for the first 2 hours. I had the Clif bar with about 300 cals, but didn't have the accelerade to keep up the calories for the last hour with my Gus. FWIW I'm 5'11" and 190 lbs.

I did notice that my calfs and arches in my feet were cramping a little after I laid down, which is something new for me. But they didn't cramp up during the run.

Any ideas?