it's hard to untangle introvert, shy, and social anxiety.
these are my definitions, as someone with all 3: introvert - i rest and recover by being alone. shy - meeting new people is more scary than exciting. i don't like being the center of attention or on stage. social anxiety - i constantly worry about what people think of me. even when i'm alone, i review previous interactions for "clues".
introversion by this definition isn't something you need to get over. you might find that you are still refreshed and recovered after spending quality time with your most intimate friends and lovers, or you might need true alone time away from even those you love most.
you get over shy with practice. meet lots of new people, at whatever pace is stressful but not overwhelming. take public speaking courses. join a theater group.
social anxiety is where it's actually unhealthy. i needed a therapist to tell me it's not normal, everyone isn't secretly, constantly, evaluating every interaction. i need medication to help quiet those thoughts. if therapist and medication are too much for you, know that most people don't think about things that much. remind yourself as often as you need to. redirect the worry to other things - did i do the dishes? is there a way to improve efficiency at work? know that working through the shyness while struggling with social anxiety is doing it on hard mode. give yourself time.
alcohol definitely shuts down some of the anxiety, makes the shy less of a thing. i was a complete lightweight, too, so half a cocktail was enough to loosen up. never life of the party, but i could engage and not be a wallflower.
but when i was back to sober, i'd have so much more anxiety about how i had been perceived while i was less inhibited. and recreational drugs, including alcohol, leave me super depressed when i'm back to sober.
i will still talk the ear off the people i'm most comfortable with.