I've completed an improv comedy class. I didn't help for me, but everyone is different so don't let that stop you, try it!. The thing for me was... I found out I'm actually really talented at improv comedy, I was the best of the class together with a girl that was also pretty good. But that was ON STAGE. Off stage it was the socially anxious me again, the sponteniety I had on stage didn't help me become more loose off stage...
But anyway, so basically, improv acting came easy and naturally to me, so I guess for me there were no nerves to conquer on that front... So I suspect that's what caused me to not improve my social comfertableness with it.
Interesting perspective. Thanks for sharing!
It's less common I think, but there are people who do well in front of groups speaking/performing, but get anxious when connecting with people more on a face to face basis.
Because your improv skills may transfer to conversation (whereas for others, coming up with what to say is very difficult), it may just take some CBT to help you learn to think about socializing in a different way and then keep exposing yourself to social situations. Good luck!