Heya! The good news is this: while I am absolutely not a doctor, this doesn't sound like any sleep disorder I've ever heard of. It also means it probably doesn't have DANGER OF DEATH written all over it in capital letters. Hooray!
One thing that you didn't mention is how long you normally sleep for. Obviously you're not in school at the moment, but I'm sure you'll remember that horrible night before the first day back after the holidays when you decide to go to bed early and can't fall asleep until 2am or whatever time you've been crashing out because your body is used to it? One of the reasons for that is that your body can only handle so much sleep. If you get up at 2pm, it's going to be difficult to go to bed at 10 because you just haven't been awake long enough. How long do you normally sleep? That could be part of what's playing havoc with your sleeping schedule.
The other thing I thought of is that while you're not working or going to school, you don't have times to stick to. In school or full-time employment, you have to be up by whatever time so that you can get to work/school on time and then you have to go to bed at whatever time because you need to get up in the morning, and it doesn't change much. You're currently in the situation where you can sleep as and when you like, which could be contributing to your sleeping problems.
My advice is to think of a schedule and stick to it religiously for a month. Think of a time to get up in the morning - 8am? 9am? Then think of a time to go to bed in the evening - 11? I'm just pulling numbers out of the air: think of some that suit you, and then stick to them. Even if you're not tired at your going to bed time, go and lie there anyway. Even if you can hardly open your eyes when the alarm goes off (yes, set an alarm!), get up anyway. It's very likely that sticking to a rigid routine will help you sort yourself out. The first few days will probably be very difficult but after that, your body will probably work out what's going on.
The BBC produced a useful quiz to help you work out what kind of sleep you need. It's mostly geared towards routine but you might find it helpful.
If you seriously believe you have a serious problem, then go to see a doctor. However, I would first try sticking to a routine to see if that helped get things back on track.
Good luck!
-Fern
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One drop is lonely
Two drops okay
Three drops can make a spray
Four drops get carried away