Why do I get a sudden nervous jittery feeling of hunger despite that I had a good meal 2 hours before? It makes me want to eat just to make it go away

Increased hunger. Increased hunger, or polyphagia, can a symptom of medical problems like diabetes or hyperthyroidism. It may be caused by stress, anxiety or depression. If you are taking medications, it could be a side effect. I suggest that you see a physician for evaluation.
Meal content. This could be a condition called reactive hypoglycemia, caused by an imbalance between Insulin secretion in relationship to meal content. Try to decrease the carbohydrate content of the meal and add more protein and fiber, to avoid an " Insulin spike". This could happen to people after bariatric surgery, for example, an dietary changes are first line approach.