Start exercising now ! (I'm not kidding - dont let your shoulder get stiff - however uncomfortable it gets - mobility is essential - and you'll only be able to do very gentle things with it at first anyway)
I was going to post something rude....but then thought better of it
get well soon jasper, and don't make any rash decisions! it will seem like forever till your well enough to ride again, but in hindsight probably won't be long at all.