Is your sleeping time your real problem? I go to bed around midnight and i wake up at 6h30. I do this monday to friday with 9 hours of work (welding and other physical work), + my 3 days work-out and I don't even feel like I would run out of energy (I know it's not good for my health, thank you)... so i don't think it's just because you're not sleeping enough... When i don't see the sun enough, or when i'm not eating well or when i'm not sleeping comfortably, that's what makes me feel tired... (I had a job once where i was working indoor 10h a day, 5 days a week in a place without much light, without any windows, exacly between the sunrise and sunset and I was becoming a zombie...)