Don't run your trans dry, never run your trans dry, it can only cause problems as you have already discovered. You may get lucky and discover that with a simple filter change and refill with fresh fluid, that you still have a working transmission. Don't expect it to do you any favors though as you weren't very nice to it. If it does work however, you can do it a big favor and change the filter and fluid again in about a week to flush out the rest of the carnage you've left behind. Don't forget to follow the trans fill and check procedure every time you change or add fluid or you'll be running with an underfilled trans!