Carbs...sticking points...
Note too that there are different kinds of carbs and the body converts them to glycogen or burns them off differently - typically, the less processed your grain and vegetable products are, the more efficiently your body will use them and convert them to fuel with fewer spikes in glucose levels
Whole wheat/whole grain carbs like oatmeal (not the over processed quick cooking kind), stone ground bread and pasta (NO ENRICHED FLOUR!), corn meal tortillas, these are the kinds of carbs you want to load up on - sweet potatos and other starchy vegetables are also good, but we do tend to load potatos full of butter and fat. Buy bread and pasta products that list the first ingredient as "Stone ground" or "Unbromated" grain - it's more expensive, but you get a lot more nutrition for your money. Your body burns these slower, more efficiently and at a more even rate than over processed simple carbs. And you don't have to eat as much of them to get the effect you want as you would have to eat if you were having white bread for instance.
Enriched flour is WORTHLESS - all the nutrition is processed out of it, then it is "enriched" by adding back in an artificial form of what was removed!
Fat and simple sugar (like a snickers bar) creates a spike and then a rapid decline in glucose levels - that rapid decline is most likely what was responsible for your nausea and vomiting - not only did you run out of fuel, but you probably down spiked your glucose level at about the same time. Eating a gel pack will reverse this quickly, but then you have another downspike coming along soon - to avoid this you need to maintain a baseline glucose level with complex carbs (an oatmeal bar pre-workout for instance), and then use your glucose spikes to create fuel above that when your workouts hit high intensity.
Sports drinks are excellent if you are doing long high intensity workouts - but caution needs to be used with these too - if you find they are making you thirstier instead of satiating your thirst, that's a sign that you need to drink water instead.
Mud?