I read this somewhere and thought I would post it since it may help you realize that you need to change something in what you're doing if you want something new. It's the definition of 'insanity' that alcoholics anonymous use. Don't take offense alcoholics:
"Insanity is doing the same thing over and over, each time expecting a different result."
If you keep attracting the wrong type of guy or girl into your life, or no guy or girl at all, change what you're doing. It make take some courage, or a lot of courage, but you have nothing to lose. Once you detach yourself from the outcome you'd be surprised at what change can bring you.