Break out of it sooner than later, the chances of finding the right girl by accident are astronomically slim. I think there's something about being young and socially anxious that really hinders people like yourself but I think you're missing out. I've always been horrible at approaching strangers and starting a conversation out of the blue. But it's more important to be comfortable and not be awkward and anxious while talking to women and that mostly comes from regular interaction with them.
Joining social groups/events that are mixed can be a good way to practice. I had a lot of this in my late teens but eventually I got over the whole fear of rejection. You have to learn to roll with the punches and you are by no means a lost cause. Look up social anxiety & cognitive behavioral therapy, it might save you a lot of stress.