Similar experience, and not much of real advice. I mostly solve it by setting up obligations by myself. However, I revert to this only for stuff that is important. Examples:

I've announced and discussed doing some boring accounting and controlling for the hackerspace, and people now expect some specific results.

On anothor note, instead of procrastinating about finding a better workplace, I gave my notice. Once I was out of the job, I simply had to start looking.

Finally, I do not need to be perfect. More people than I expected have the odd day or two during the workweek, and knowing this I have reset my expectations regarding my own performance to something more humane.