Straightening the Derailleur Hanger
It's pretty easy to bend the derailleur hanger when you fall over to the right side. The derailleur hanger is the thing that sticks down behind the right dropout (rear wheel axle slot in the frame) to attach the rear derailleur. On some bikes, it's part of the frame. On most upper-end bikes, it's a separate piece of metal, designed to be replaced if it's damaged. (Even if the hanger is a separate piece of metal, you can use this technique to correct a minor warp. But, my suggestion is that you always have a replacement hanger available.)
A bent derailleur hanger can make the chain jump between rear cogs, can create "chain suck" on the front chainrings, or will make the chain jump off the front chainrings when backpedaling.
Grasp the bolt with your hand, or a wrench. Using the leverage at the end of the bolt, tweak the derailleur hanger until it appears straight.
Now test in the the up/down direction. Establish "vertical" along the seat tube. Sight along your carpenter's square to see if the your bolt needs to be tweaked upward or downward.
Check and adjust the shifting of the derailleur . It's very likely that you tried to adjust the shifting before you realized the cause was a bent derailleur hanger. So, everything you messed up needs to be re-adjusted.