This is why this bizarre thing happens when you procrastinate. You don't work on the project that you should be, nor on the project that you'd be working on if you were free to do whatever you want. Instead, you end up doing the kind of stuff that ranks somewhere like four or five on your preference list. This is the time when you watch an entire box-set of a television series you like, or you alphabetise your DVDs. Stuff you enjoy, but you wouldn't usually do.
But in understanding this, you can actually do something about it.
First I should say, of course there are other things 'procrastination' can mean. Sometimes a person genuinely prefers going on facebook, or watching the DVD box-set, and it's other people, not the individual, who have decided that they're not doing what they should be. But I'm not talking about this kind of thing. The solution is too easy: ignore them.
The kind I'm talking about is most pecular to people, because they actually love the things involved. On the one hand they have X, a project they love and do regularly. On the other hand they have Y. Y is the kind of thing that you would enjoy doing, maybe even quite similar to X, but you don't yet feel motivated to do it for its own sake. Unfortunately, you have to do it, because there's a deadline looming or it's important for some other external reason. You love X, and you will love Y, so you'd think picking one of them would be easy. But it's not, you pick Z instead, something you kinda like but never normally pick. Why? Because of self-coercion.
We so readily accept guilt and worry as legitimate ways of motivating ourselves. I personally think it's a hand-me-down from how many times (particularly growing up) other people used guilt and so forth to coerce us. But the consequence of this is that we don't do X, as we normally would, because doing X would remind us that we're not doing Y. And we of course don't do Y, because guilt isn't actually a very persuasive reason to find Y enjoyable. So we pick Z, specifically because it's different enough from Y and X that we can forget all about them.
The solution, as bizarre as it might sound to people, is to not try to force yourself to do Y, especially by means of guilt or shame or anything else like this. Just embrace that you really want to do X, and be happy about that.
Now, at this point, you might say: but what about the looming deadline?! But doing X instead, IS the solution for how to start doing Y.
It's true that you might actually be better off doing Y, but you're not going to be motivated to do Y unless you allow time for yourself to be positively inspired to do it. Say X is write a play, and Y is write your university review on someone else's play. In doing X, you give yourself chance to be inspired to do Y, either instead, first or afterwards because X will be similar enough to Y to allow for this. (Remember, this follows logically that they're similar enough, from the fact that you have to pick Z, not X, to not think about Y).
Once guilt is out the picture, this positive inspiration can take hold quite quickly. I've known it take minuets even. On the other hand, of course, this doesn't happen when you pick Z (say, facebook) because Z has been specifically picked because it lets you forget all about X and Y, so there'll be little or nothing to remind you of why Y is good/fun/interesting.
So in summary: If you want to get rid of this kind of procrastination 1) let go of guilt and be OK with doing what you really want, and 2) do what you actually want and let that be the inspiration for doing other stuff, too.