Over torquing a lug nut can do just as much damage. Do yourself a favor go to the hardware store and get a torque wrench. For the love of god do not get one at harbor freight.
What you need to do is take the wheels that where "wobbling" turn the wheel around to where you can see the backside of the wheel hub and inspect the lug holes. Make sure they are perfectly round. You might have caused the lug holes to become egg shapped which can cause a wheel to come off or crack in some points.
Reference picture (this is not my picture just found it on google)
