heard from the doctor

I have been struggling with fatigue since my surgery. I really feel like something is off. I went to the doctor and had some bloodwork done. Everything is normal. What does this mean, am I just lazy. Why can't I find the energy I should have. People are supposed to be full of vim and viggor after losing weight like I have. I am going to take the new medication he gave me for a month and see if that helps. I was really hopeing for a reason for my lethargy.