Chances are something fell inside and is now jammed between the rotor and the side wall of the disposal. If you're not comfortable removing the unit and disassembling then get a new one and call a plumber (or handyman) to install it.

Hi... I agree with spookyoldtree.... however if the GD is not that old and ready to be replaced anyway... you might buy a straight 90 degree allen wrench (I assume you have the one that is bent on both ends that comes with a GD) and try putting a "cheater" (a hollow small pipe... like maybe 1/2 " copper pipe) on the end and over the allen wrench to get some leverage and work the H out of the rotor back and forth. Most times, it's difficult to get enough force on that small allen wrench when under the sink to break loose that tab top or rock or whatever is jammed.

Usually, whatever is stuck will break loose with enough force... and if you were to damage the GD... you were going to replace it anyway.

Good luck

Peter

I have little doubt you've got an unusual jam of some kind in there. You WILL be able to see it from the top. Take out the rubber thingy to give yourself a larger visual opening for inspection and get a flashlight so that you can really see in there. I'm almost certain you'll see the problem.

Since the jam is that solid, you'll also want to inspect the circumference on the inside. There may (or may not) be damage to the cutting surfaces from this unusually solid jam.