First you should discern whether you are lonely or just bored. I know of many who confuse the two.
The solution for both, however, is the same. Get out and DO something. Find a song that really gets you and make a guitar soundtrack for it. Pipe your guitar audio into the computer and experiment with computer-based FX. (There are some wonderful FX you can do through a computer, and all for freeeeeee!) Go try a new restaurant you have never been to.
Don't wait for somebody else to be with you before you start living. Get out and LIVE!