Sometimes, I do feel guilty for playing games, especially since that time can be better spent working on other stuff. Still, it's not that hard to strike a balance between doing productive stuff vs non-productive stuff that makes you happy. Denying yourself gaming entirely can be just as bad as playing WoW 80 hours a week. My life is sort of lacking balance between internet and real world time, but at least I'm aware the issue exists, and I work on it by making an effort to be more social, and break routine to do new stuff whenever I can.
On the friends disappearing issue, that's a perfectly normal part of moving on to university. For my part, my university friends scattered to the four winds when the program was over, and it meant I had to work to keep the ones I had, and to make new ones by trying new stuff that involves other people (sports, martial arts, etc). Your network of friends will always be in flux as you move through life, so what you experienced is hardly caused by gaming alone.
In any case, don't sweat it too much. I learned some very valuable financial lessons for real life by playing video games (example: investing in harvesters instead of tanks now gets you MOAR TANKS later = investing for the future is good), so it's not all bad. Just make sure it doesn't consume too much of your time.
Super World Cup Fighter II: Championship 2010 Edition
