I am trying to go primal, but I'm having a terrible time eating correctly during frisbee tournaments. Help!

Several weekends a month, I play serious frisbee tournaments. This usually consists of 4-5 games on Saturday and another 4 games on Sunday. Each game is over an hour long and involves jogging and intermittent hard sprinting. If you're not familiar with the sport, think of it as soccer. The schedule can vary a lot within the day - I might have two games in a row and then an hour break and then another two games, for example, but it's usually around 8 hours total with 5-6 hours of playing per day.

I've tried eating a big breakfast and then eating sweet potato, dried fruit, salad, bananas with almond butter, apples and other primal foods during the day, but it's just not working. By the last game, I'm totally out of energy and resorting to candy, chocolate, and straight sugar to get me through. It's hard to eat any real meals during the day because there's not enough time between games for my stomach to digest anything serious.

Does anyone have any experience with this kind of exercise schedule? What would you recommend to keep my energy up?

PS. I tried searching the forum for this topic, but was unable to come up with anything quite like it. Happy to be pointed to other threads though - I am new here!