Hmmm. First, what's your motivation? Do you still love your work? I know from experience that no matter how hard I try, or whatever tricks I pull out of my bag, I simply cannot force myself to work on something I've lost interest in. Oh I can muster up some effort for a short time, but I think doing so wears a person down after a while.

That said, here are a few pointers:

1) According to David Allen, there are only two reasons for procrastination: The task is either a) overwhelming (too big), or b) not motivating (unpleasant). (More at Some David Allen "twos" - two reasons we procrastinate, and two kinds of problems.)

2) Try the the "STING" method:

S - Select one task.
T - Time yourself.
I - Ignore everything else.
N - No breaks.
G - Give yourself a reward.

(More at Use the STING method to stop procrastinating.)

3) Finally, how about this thought: "Motivation is not a prerequisite for showing up." It's from Patricia Ryan Madson's book "Improv Wisdom: Don't Prepare, Just Show Up." (More at Great time management ideas from the world of improv wisdom.)

Good luck!