I'm wondering if I have sleep apnea or if this is just the result of spending years in jobs that had me bouncing between day and night shifts several times a week.
Could be that if you feel like crap almost every day. Time shifting sucks, I have a neighbor that works time-shifted and he's literally slo-mo every day.
It frustrates the hell out of me because I don't drink alcohol, don't use over-caffeinated energy junk, and have an alarm loud enough to annoy the whole house, yet I still somehow wake up late and feeling like a train wreck. I'd try exercising more, but it's kind of hard when I don't really feel okay until evening, when exercising would interfere with sleeping.
It might be the stress from work (that shifting you mentioned). Like C17 told me,
The best advice I can give is 1.) see a doctor 2.) exercise regularly, eat healthy, and meditate or perform some action to clear your mind before going to sleep and you should have no problem fixing your sleeping patterns.
Although I don't metitate, usually I'm walking or at the park with my dog after my snack and breathe some fresh air with him. You can try exercising before washing your teeth, to get those bones and muscles in proper order for the day that is coming.
Cheerzzzz