I can't help but switch into "I'll be your stupid slave if it means I get to be with you" mode

Whatever it takes, you have to kill this part of you, or you're gonna have a bad time. My advice is to focus on a challenging feat of pure physical awesomeness. This is going to do a couple of things for you, namely it's going to take your mind off of your loneliness, but it's also going to get you out of the house, and that's where the other people are. You should really want to meet them, because great relationships happen when people are introduced through groups of friends. Start now, because the older you get, the harder it is to meet adult friends.

Start small, focus on completing a local 5k, and have an ultimate goal of doing something sick like a triathelon or GORUK type of event. Think of it as a video game and you have to level up. Get information on starting a running routine, and just keep leveling up. You'll get in shape and you'll meet people. You eventually have chicks chasing you, because you become so focused on completing your new game, that you'll completely ignore them, and then they'll wonder, "what's so bad ass about him that he ignores all of this hotness," and that young Jedi is how you eventually beat the game.