Energy, where are you?

Ever since we came back from skiing I have been just too tired and I have struggled getting up. Since my workouts have to happen before I go to work, that essentially means that I have had zero energy to workout. I am not sure why that is. It is true I have been working a lot and I am not necessarily going to bed early, but I think I have been sleeping more than I was last year. Maybe it is just the winter that is getting to me.