Whenever I eat I can feel the food in my stomach for hours. My stool is also hard and not regular. I also feel gas inside me.?

Gastroparesis. Usually the stomach empties of solids in <1 hour after eating. If your food is hanging around, you may need to be evaluated for gastroparesis (slow gastric emptying) or a gastric outlet obstruction (goo).
See your physician. A number of things can cause this including: gastroparesis, severe constipation, hiatal hernia, severe reflux disease, partial bowel obstruction...The main thing is the above symptoms are not normal and not likely to go away on its own. See your doc to get evaluated and find the cause so you can be treated properly. In the meantime, try to increase your water intake. Good luck.
Many possibilities. More information is needed. It could be something as simple as constipation to ibs (irritable bowel syndrome) to something more concerning like gastroparesis or worse. You should get it checked out.