When I have something of a work-related nature that I want to accomplish, I tend to stay up late working on other things or sometimes just goofing off. I don't go to sleep because I know I should be doing the thing I'm avoiding. My hours get switched around from time to time as a result depending on where I am in the week.
Yes, I have exactly the same problem. I don't go to sleep, but I don't do what I 'am supposed' to do either, even if I don't dislike the thing I am supposed to do. I avoid thinking about what I have to do by reading forums, watching TV, listening to the radio or by doing anything that is able to keep my attention away from the things I have to do. It's pure escapism and I usually fail to get out it once I have started to stop thinking about what I had to do. A half conscious feeling of: "I still have work to do" that pops up now and then keeps me from going to bed. However I do use quite some tricks to avoid getting in such a situation in the first place. They don't always work, but so far I am somewhat content about my 'solutions'.
My biggest escape machine is my laptop, so at the end of the day, I usually remove it from my desk and place it somewhere out of sight. This is to prevent me from starting it up without having consciously decided to do so. For the same reason, I don't even have a TV. (I live in a students house, we have a TV in the shared living room)
Another thing that often works is making a quick scedule. I write down what has to be done, even when it's trivial and I won't forget it anyway. For some reason it has more 'weight' when it's on paper. I think it works because it takes some time to write something down, so you don't have the chance to procrastinate it in less then a second without me actively being aware of it. It forces you to consciously make a decision about whether or not you are going to do it right now, or any time later. I usually use the back side of an envelope which I throw away when I've completed the things written down on it.
A final thing that can work great for me is organising social pressure. When I have to study, I agree with others to meet at the library. Things like that.
Relying on tricks like that may feel a bit weak. It does for me at least. The cultural determined idea is that when you have a minimum of wisdom, you can beat procrastination, because it's totally irrational. Relying on tricks is accepting that your own motivation and common sense is sometimes simply is not enough to get you started and that's not a nice thing. The flipside is that it works, while telling yourself that you don't need it and you'll stop procrastinating tomorrow doesn't. I doesn't always work, but things surely have improved since I started to force myself to do thing I already wanted to do.
I'm neither of those, and I'm not lazy either. It's an anxiety thing.
It's interesting you mention anxiety. That is an issue for me as well. Even when I was (and still am) very confident of myself, I didn't want to be confronted with situations which theoretically could prove me that I had been overconfident. I.e. I didn't prepare for exams, so if I failed them, I could blame my preparation. It may be anxiety not to live up to my own or others standards. I'm not quite sure though, it's just what logic tells me.