I know exactly what you mean! I used to be a person who HAD to be under the influence of a substance of some sort just to interact with others in social situations, and just two weeks ago I went to a party with over 50 people present and only ONE person I knew (and even she was just a girl I barely know), and managed to have a great time.
At first there were thoughts of insecurity and social anxiety, but I remembered to focus on breathing and observe my thoughts and emotions instead of identify with them, and within minutes, I had calmed down completely and managed to make a plethora of new friends
YAY to continued success for us all!