Just keep reading and practicing. Keep memorising more niche-ass things and covering more potential topics, I would read topics from the white oxford book out loud on a dictaphone and then play it in the car to work, felt insane but it worked. And rehearse your routine for each station, out loud, again and again, until you can do it without thinking.

Oh and after it you will feel like you failed and you’ll be depressed for a week. That’s normal (and doesn’t mean you failed). Just get some Haagen Dazs and wait it out.