I can eat a full meal and be completely full then in about an hour i'll be starving again. is this normal? my grandma had diabetes not sure what type.

See a dietitian: The types of foods you are eating have a big effect on how soon you feel hungry again. Meals with lots of fiber and protein are more likely to keep you full than meals high in carbs and sugar-containing beverages. Your risk of developing type 2 diabetes is more related to overweight or obese than what you eat though sweet drinks do seem to increase risk. Suggest you meet with a dietitian

Unfortunately this : Can occur without any concerning pathologic process like diabetes. There are many reasons that have lead predisposed persons to limited ability to "recognize" satiation, like what is found in binge eating disorder. It's something that you should review with your primary care doctor.