Have a cuppa tea and write a list of jobs in order of priority. As soon as you finish your tea you have to get working. Then crank up the music as libby suggests! Whistle while you work! :o)
If the internet is distracting you (!) switch off the modem and set the pc to do a full virus scan. This should hammer the performance sufficiently to deter you from surfing.
www.flylady.net and follow the link for crisis cleaning. then implement all the routines and heed her advice.
It took me 5 years of being on the mailing list before I actually stood up and did it that I lamented for not doing so earlier.
If you take your 'baby steps' and gradually implement these routines, next time you have a day off, you can plan something lovely instead of having to house work.