Go travel, visit some friends overnight, go camping, anything to get out of the house and create new (or at least different) experiences and a bunch of simple-but-different problems you need to solve. When you're done and get back home, you can reintegrate to the Internet, catch up, and hopefully not feel too guilty about it. Spend your willpower making sure you get back out there, rather than trying to police your default behavior.
If that's not possible to due a lack of money, friends, physical ability, etc, then I'd say you are dealing with serious depression and professional help is not unwarranted.