Booth -

Your tuber if you pot it again - will give you new stem and new buds. Your snapped stem - you need to remove all buds, big lower leaves - and it will root easily and give you a new tuber in no time, probably a bud, but if not - you will get them next year.

Sh-t happens. But you didn't lose the plant, after some rest the old tuber will send you another stem and you will enjoy your blossoms.

Usually after the bloom is over, I let them grow for some time to accumulate energy - and then remove a tuber, wash it, store it in a baggie with vermiculite - and as soon as it sends a new grouth - I pot it again.

To have 2 gloxinias is better than 1.

Irina