I overwound my clock

Well, no, you probably didn’t. Now unless you were winding it and heard the clock movement explode.  You would know if that happened!

Your clock is fully wound up, but it is not running.  May I use a car analogy?  If you fill your car with gas, but you don’t drive it, it’s not going to use any more fuel, and the gas tank will remain full.  In the same way, your clock is “full” and you can’t put any more “gas” in it.  Something is preventing it from running.

Overwinding could have been a problem centuries ago, when clock manufacturing was much limited by the mainspring steel, and the springs could catch on each other rather than slide as they unwind.  I have only seen one reference to being overwound in any repair manual (late 1800’s)  and that was referring to a rusty watch where the mainspring got stuck.

Sometimes people get distracted, and they forget to wind one of the arbors, or they try and wind it in the opposite direction, so you might want to check that out.  But if it’s wound up, it is (really) wound up, and not over wound.