Writers block

I set myself the target of completing another chapter of my thesis by the end of this week but am completely lacking in motivation. I think it's because I'm stuck, I just can't seem to make what I have written flow properly and can't think of what to write next. It doesn't help that I'm still having to go into work all day to finish off the analysis of my last set of experiments. The last thing I feel like doing is then to come home and start working all over again. It might help if I knew I was going to get a job at the end of it but although there are a couple of irons in the fire, nothing is certain. At the moment I don't seem to have the self discipline - a firm deadline might give me the kick up the arse I need.