That was me many moons ago. I too would enjoy small friendly groups but hated big parties and was never good at casual small talk. Alcohol became courage juice to overcome being introverted due to shyness and self-consciousness, especially at single's places. We're talking late 70's and early 80's in my case. I don't know... about 35 years ago I stopped drinking and eventually became comfortable in my own skin without alcohol or anything else. Now I can go anywhere to any group and enjoy myself, and would probably classify myself as extrovert. Back then there was no "online" as such, BTW.
I think the key is to realize you are okay and you can be comfortable in your own skin. Not everyone has to be an extrovert. Not everyone will like you or even want to talk with you, I had to learn that. An old friend told me once "If you walk into a room of 100 people, 30 will not like you no matter what you say, how you look, etc.".