Find a hobby which does not require a computer.Try doing sport, read, exercise, keep a diary. Go down to the library & find a good book. By trying something new it is a great way to meet new people.
It is a chore! I am in the same position, but it is harder for me because I am sick in bed most days. :( I have to make an effort to simply go sit in the sun, read a book for at least 20 minutes, or focus on some other activity like crafting.
I find a good way to make yourself aware of how long you've been on the computer is having a timer nearby. Set it for half an hour, 40 minutes, or an hour, and when it goes off, no matter what you are doing, WALK AWAY from the computer! Make yourself do something else for the next 20-30 minutes! You'll find you have a much more rounded, complete life when you do!