It always happens, every time - after going through a period of being overworked ("riding the wave" as one freelancing book I read called it), I get burned out and start missing deadlines.
Another thing that I can always count on: about the same time, I start feeling under the weather.
I think it's all related, actually. I start missing out on sleep in a major way since I have so much work to do; my immune system starts slipping; and by the time my workload returns to normal, I've lost the emotional and physical endurance to push myself any longer.
I'm going through that right now. It doesn't help that at the same time, I've been frantically working on planning my wedding. Michael and I are getting married at the end of April, and I just got the invitations off a few days ago. That was a relief, but it was like pulling teeth to get it done.
I spent Saturday, Sunday, and Monday nights catching up on sleep, in the hopes my immune system would recover and kick whatever it was that one of the kids I babysit for had exposed me to. I spent Sunday and Monday dealing with wedding stuff, Tuesday redesigning my website, and Wednesday babysitting again. (Naturally, the kid is still sick.)
I'm hoping to be able to get my butt back into gear tomorrow (Thursday), so that I can get at least two productive (read: money-making) days out of this week.