Well, Doc, my mom thinks I spend way too much time gaming (which is probably true), and she isn't one of those psycho anti-gaming parents that thinks games should be purged by purifying holy fire, she just wants me to go out more and meet new people. The problem is way back in my elementary school days kids decided that being douche bags to me was awesome, so now I'm extremely cautious about talking to new people and have trouble carrying conversations with people I don't consider friends. Which, as you may be able to guess, puts a big damper on what she wants me to do.
I'm in no way one of those social recluses that puts blackout curtains on all their windows and hisses at sunlight. I go out every Friday to an MTG draft and try to get together with some friends to play D&D as much as possible, but most of my week is spent inside on my computer. Do you have any helpful tips so I can get out and not be so damn nervous about talking to people? To put it into perspective a bit more I've worked at my job for a little over a year and barely speak to anyone there.
In my experience, social issues can be a big factor in intensive videogame play. Some folks come to gaming with significant anxiety and find relief in engrossing games. They enjoy a new kind of social connection where it's possible to share only a part of themselves, or project a persona more consonant with who they want to be, rather than who they actually feel they are.
I have known some people who have a very active online social community developed through gaming that includes many real life friends and some online relationships. Parents are naturally skeptical because they don't see how playing a game on the internet could really be "hanging out with your friends," but for growing numbers of kids, that's just what it is.
In your case, it seems like gaming has been a place to retreat from aversive experiences and feeling comfortable only with certain groups of people in particular situations. It's a good sign that you realize these limitations are problematic - it can't be a good thing to barely speak to your co-workers after a year on the job.
I think the most benign way to address this problem would be to try expanding your comfort zone gradually. Perhaps you could arrange to do some things with your MTG or D&D friends that would involve meeting new people or going to new places. Each of these experiments would be intentionally contrived to put you in a situation where you would have to stretch a little bit. You'd have to push yourself to overcome your inhibition to talk to new people. Hopefully, you would get some positive results and your discomfort would slowly diminish. It might help if some of your friends were better at this, and you could, at least in the beginning, try to emulate one or two of them. There's no harm in a little acting if it primes the pump. You may not feel like yourself, but you may start to feel calmer and more confident in these situations.
Your Mom is probably hoping you will start to develop a community and some significant relationships that will help you move forward in your life. Most parents are happy when their adult kids move out and show they can handle an independent lifestyle.