Changing chord gets better with practice.. Your building muscle memory..
Hopefully your med problem doesn't slow that down..
Try doing a two chord switch.. use a simple strum pattern. I liked E to Am. , then Am to D.. then C to Am... F to C and so on.. get a few changes down and then go for three chords.. Get a few three chord changes down then go different rhythms...
Hope this helps you..Good luck and get well soon
Gordon
