I took the rear left tire off and looked inside. So:

-I loosened the bleeder valve, seeing if it would decrease the brake pressure. Nope; still couldn't turn the wheel forward.
-Tightened the bleeder back up and took off the brake caliper, even the brake pads. Still couldn't get the wheel to turn forward.
-The wheel can turn backward, but just barely, in either case.
-Put everything back together, started the car. ABS and Traction Control lights remain on. Tire still sticky when I go forward.

So... what could be the problem?

Your brake shoes inside the disk brake rotor has locked up so thats why it turns one way but not the other.

Ah I see. I park my car on a slanted down drive way, so I use the parking brakes a lot. I guess the rear left wheel just didn't release properly this time.

So what would be the next step? Is there a way to release the brake shoes manually without absolutely taking everything apart? Is this a sign that something needs replacing?

You fried the park brake shoes by continuing to drive it. You have to take the rear rotor off to investigate what damage occured. If you don't there could be chunks of brake material that could stop your wheel and cause the tire to lock up. More than likely the shoes are wasted to just replace them to be safe for you and others arround you. Check out on Youtube and search under replacing park brake shoes on the camry to get an overview of this procedure. You went this far...don't stop now.

Ok will do. I didn't drive that far, but I'll do what you said just to be safe. Thanks man.