I think I have found the solution:

Information online tells you to drink water, water, water and maybe gatorade if you like. Well, I am suggesting trying an electrolyte formula - such as the following from Clif. This is probably going to do more for you than the high fructose full gatorade crapola. I've purchased some and will be trying it on myself in the upcoming games to see how I fare. I will hydrate myself with this before the game, have a water bottle full during the game and use it after aswell. I'll keep you updated on how well it works!

Update: The stuff works! I usually drink two pint glasses before the game and then a cooler full during the game and then a pint glass when I get home. I still feel tired - dont get me wrong, but I dont get the immobilizing headaches and vomiting like I used to!