Burning or gnawing feeling in the stomach between meals or at night is suggestive for gastritis, an inflammation or irritation of the stomach lining.
The same burning pain can be also, due to painful sores or ulcers in the lining of the stomach or first part of the small intestine, called the duodenum (stomach and/or duodenal ulcers).
When pain is more prominent when hungry or before meals, eased with food and pain that may wake you up from sleep, is most likely due to peptic ulcer of duodenum.
If the pain is more prominent after meals or when you are eating, you are probably having a stomach ulcer (pain is triggered when food comes in contact with damaged stomach lining).
Duodenal ulcers are more common than gastric ulcers, but, it is possible to have both of them at the same time.

See a gastroenterologist!