I concur with this comment about social anxiety. After incorporating some mindfulness meditation into my daily routine, I have noticed a stark decline in how much I replay conversations (as per another comment here) and how much I rehearse potential future conversations (which never go the way you rehearse! Off topic: Mike Tyson’s quote is good here: “Everyone’s got a plan until they get punched in the face.”). I think both of these acts (past rumination and future rehearsal) are big parts of social anxiety that lessen with mindfulness.

As for having imaginary conversations with real people I know that are neither repeats of past conversations nor rehearsals of future conversations, I think there may have been a slight decline but I didn’t do a ton of this prior.

TL;DR: I think mindfulness meditation helps with this.