So tired , but can't sleep

How can a person be so tired and not able to sleep? I even took two melatonin, but that hasn't helped. Guess I will start reading a new book given to me recently. I love to read. I made turkey soup today. My husband said it was good. I haven't eaten any of it yet. When I eat my stomach gets very upset. Hubby took me to the doctor yesterday. Will have some xrays,tests, an ultra sound on gallbladder on Friday,
Dec 4th. Hope that will determine the problem.