Hunger Pains/Contractions

I'm a 16 yr old female and I suffer from hunger pains/contractions. These often happen about 5 or 6 hours after eating and usually after or during a short plane flight. These hunger contractions are very painful and makes it hurt to breathe or move about. I know that hunger contractions usually only last about a minute or two, but mine often last somewhere between 5 minutes and half an hour, or until i eat. The last time i got the severe hunger pains me and my family were just getting off a plane flight on holiday and as i am overweight they assumed that i was lying about the hunger pains and that i was just being greedy, and therefore would not allow me to go and buy food. I am due to go on holiday again in 2 weeks and i am scared to get the hunger pains again because they are the worst pain i have ever experienced.
Seeing as i can't rely on my parents, does anyone have any helpful suggestions to stop the hunger contractions?