A lot of all these posts telling you to be more extroverted is crap.
Yes, go be someone you're not, get out of your comfort zone, and inevitably look ridiculous to please someone else, then eventually change back to yourself later and have her hate you for it. Or hate the relationship because it doesn't jive with who you are.
You need to go to a good concert/bookstore/gaming store, or -bluntly-go where there are things you like, then you can find a common ground with someone. It's a starting point. All of what you're saying makes perfect sense to me. You need space. Not a girl who's calling and whining and won't leave your apartment. Honestly, the number one reason I married my husband is because he doesn't get on my nerves, and that is rare for me and dating. Many people think that's strange, but that's just because it's not what they would do. 15 minutes into dates, or get togethers, I wanted to run screaming from the car. People see through their own lenses. Find out what makes you happy in life, and then find someone to share the ride.