Vomiting/headache/dizzines if I wait too long to eat have to snack all day - not pregnant - what could this be?

Sugar. If it is eating-related, most likely related to how your body handles sugars. Sometimes if you are heading toward diabetes, your body compensates by sending out extra insulin. Your body is stressed, listen to it. Quit skipping meals and have healthy snacks with you, snack every 2 hrs at most, see your doctor for further evaluation.