How can I make it as difficult as possible to connect to the Internet from my "work computer"?

I don't want to sound offensive or off-topic, but it might be that you should work on your anxieties, your work habits and such, not on tools you use.

Been there, done that. I've learned to circumvent all the technological means of disconnecting the Internet I could think of (it doesn't help that I'm a programmer by trade).

My advice is to seek professional psychological help. Change your ways so that you don't mind your superuser reputation (or any Internet distraction) that much. Good luck.

Restrict access to your laptop's MAC address on the router - then you'll need to go to another machine and disable it before you can move on.

You could also block port 80 to your machine ONLY at certain hours of the day when you're meant to be working.

Uninstall your network adapters :D