When socializing is like pulling teeth.

Guys, I really suck at maintaining a social life. My girlfriend moved out and away to California for a new job, so I'm flying solo right now. If it weren't for my job and groceries, I probably wouldn't leave the house. I'm trying to make plans with a friend or two for tonight, but it's only because I feel like I should and not because I really want to.

The stupid part is that I've been feeling really lonely without my girlfriend around, but still I can't find the motivation to socialize. What the hell is wrong with me?