D..
I used to be a wonderful sleeper, M.. Then I got sick and my health problems lasted for a long time. On top of it, I was going through menopause and I think that allowing my brain to get used to not sleeping somehow "altered" it.
You say you are a night owl, but you are playing with your "rhythms" too much and causing yourself a lot of problems. Here's what I would try if I were you:
No TV an hour before you want to go to bed. Pick a time and stick to it for a whole month. Make it 8 hours of what would hopefully be continuous sleep. An hour beforehand, lay down and read a boring book. That will get your mind prepared to sleep. Having a fan in your room or white noise will help as well.
Don't drink ANY caffeine of any kind after your morning coffee. You think that the caffeine isn't kicking in at 11:00 pm, but other forces are at play. You need to cut the caffeine substantially (not all at once, and not all of it. Dropping it all at once will cause you headaches from withdrawal.)
NO MORE NAPS. Sorry - you really have to stop the naps during the month of changing your rhythms. During this "tired time" is when you should be cleaning your kitchen, even if it kills you to do it.
Make sure you are drinking plenty of water during the day. Don't eat after 7:00 pm, and don't do anything physical (other than good ole sleep- inducing sex) after you lay down for the night (with that boring book.)
If you do all this, every single night for a whole month, and it still doesn't work, you need to get a sleep study done with the doctor.
Really and truly, lack of sleep can cause you tremendous problems as you get older. Don't let it happen to you. I work very hard to get sleep - it is indeed precious and people who don't have trouble getting it don't understand how devastating continuous lack of sleep really is.
Dawn