Sorry about your wrist. Here's wishing you a speedy mend.
I take a spin class once a week, and it's the best thing that's ever happened to my bike fitness. That would be the choice I'd recommend to you, as it's much harder to push yourself when you're just pedalling on a trainer at home, or riding a staionary bike at the gym. Additionally, those stationary gym bikes many times don't even put your body in a "real" bike position.
Another thing you could do is... anything *but* cycling. You could use this "downtime" to try as many different sports/activities as possible. That way, you'd be putting your muscles through a wide range of activities, giving your cycling muscles a break, and you could even come back stronger. Or find another sport to love and xtrain with.