loneliness is the worst. I am sorry you are experiencing it.
I have said it numerous times, when we are having social difficulties sometimes it does us just as well to look without as it does within. Consider those people who we see as being successful socially. Is there anything you can observe that makes them so successful? Recognizing these characteristics and behaviours is it possible to role model some of them to your own benefit? Learn too from observing behaviours from those that put you off. Remember that effective non verbal communication is paramount to successful socialization.