Dude try to text them..do parties, watch movies together..or go with them somewhere so that you can feel comfortable again And try to use Net daily only 3-4 Hours..
Try to find a new hobby that your friends also do. The more things you can do with your friends the more time you will spend off of your computer.
This all comes down to inner body will, you have to tell yourself well almost force yourself to meet up with your friends and speak to them and see what differences can be patched with a similarity.
You don't want to talk to them because you're afraid what they might think of you since you haven't saw them in a while.
Just talk to them anyway, weather what they think of you.