I used to have a wierd stomache pain in 7th grade, everytime I got hungry it almost felt like someone was punching / kneading me inside my belly, and my stomache would hurt at periodic times through-out the day. I never got it checked out because it disapeered. The pain came back sporadically through-out highschool and hunger really hurt (more than it seemed to affect anyone else I knew). After my first semesters exams in college I got something like what you seem to be experiencing. I had to eat literally every 1-3 hours to stave off extreme hunger and sometimes it hurt so bad I couldn't bring myself to eat. I couldn't fall asleep.
Long story short, it got so bad it couldn't be normal. I went to the doctor and they diagnosed me with this bacteria after doing some blood-work. Evidently over half the world has it in their stomaches, its symptoms don't always appear in everyone. The pain can trigger on hunger, stress, smoking and a bunch of other things.
For the longest time I was afraid I had a tape worm in my stomache because of how often I was hungry and it hurt, I didn't believe metabolism could be that fast / hurt so bad:
If you still have similar pain and haven't figured it out go to the doctor and get tested for:
Helicobacter pylori - Wikipedia, the free encyclopedia
EDIT: Wikipedia seems to talk about the science behind the bacteria but if you google for it you'll get a lot more stuff that might or might not relate to what you're feeling