GETTING UP EARLY

i am doing research on how can i get up early,i found different sites and i am comparing results, as soon as im at work (obiously is roofing), i can work hard even not take lunch only water all day, i can stay up late, but in the mornings i feel like a ton i dont know if its just lazy, or something is wrong i also wake up with the worst dry-mouth and so tirsty even if i gulped water all day, on the roof can get pretty hot somedays,but if i go to bed late or early dont make any difference once i am in , I AM IN!!, and gettin out is very hard for me, this affects my overall day production and i dont want to be lazy anymore, some friends work just as hard, go out drinking , dancing and they are the next day at 7:00 on the job!!, at least their body is , , some people say is just lazy , but for all i know it could be a sleeping disorder or something, HELP!!!