take your computer to a friends house and ask them to mind it for 2 weeks and not to give it back under any circumstances for the whole 2 weeks. Without it you might get bored and start to do something else to fill in your time.
If you start to withdraw keep reminding yourself its not for ever the pc is coming back. Maybe even just drop it off for a week.
Suggestion to pass your time
* Ring all your friends and organise to have a coffee or go out
* Go to a neighbour hood house and start a class or attend a social activity.
Before you get rid of the pc, google neighbour hood houses and community centres for activities. Search for activities and entertainment in your area so you have some ideas of what you can do.
Go to the library,b orrow a book adn sit in the park and read it
Go for a walk, join a gym, go for a swim
Or maybe even start off small, join in on a group or activity for 1 night a week then use the pc when you get back. and maybe you will feel good coz you enjoyed doing something different.
another idea, set rules and stick to them like you will only use the pc after you have done other jobs such as housework and gone for a walk or something. make the computer time a reward for after you have done other activities.