I cannot sleep one full night if I go to bed early

[Laurelindo]

The thing is, I am without a doubt what most people would consider a night-owl - I enjoy staying up late, and if I have no real reason to go to bed early then I will often stay up until 5 AM, and sometimes even longer. So maybe it doesn't sound so strange that I would have problems falling asleep early. However, my problem is actually quite the opposite - I do fall asleep early without much problems at all, but instead I always wake up in the middle of the night, around 3 AM, and then I cannot fall asleep anymore that night! This happened a couple nights ago, when I went to bed quite early, especially by my standards (10 PM). I would have natural awakenings at midnight and then again two hours later, but after that second awakening I just lied there and tried to relax, and just fantasized about pleasant things, and tried to avoid making it an effort - but after almost four hours I started to feel really impatient and thought to myself "this is ridiculous, I'm getting up now" - and then I ended up feeling incredibly sleepy that day. So my problem isn't to actually fall asleep much earlier than I'm used to, but rather to stay asleep until morning. How long do you think I will have to deal with this before I can sleep one full night without having to go to sleep extremely late? It is actually kind of frustrating, it would be so pleasant to get up early in the morning and actually feel rested.