2013 honda fit brake problem?

I have a 2013 honda fit. Heres what's going on.

When i'm driving forward, the left rear brake locks up SUPER easy. Doesn't matter if i'm using the foot brake or emergency brake it locks up too easy. I jacked up the car with the e brake off, and went to spin all the tires and with all brakes off, all tires spin freely, then when i pull the e brake, both rear tires won't move, just as they are supposed to. So i took of the rear left drum and the brake shoes have PLENTY of material left on them, and the brake drum is also in really good shape, same goes for all 4 brakes. I tried going in reverse and slamming on the brakes, which was supposed to adjust them or whatever, that didn't work, i tried pulling the e brake a few times while stopped and while rolling, that didn't work, brake fluid is clean and full. What could be the problem.

It is best to see a mechanic. Could be a problem with the brake springs or a sticking brake cylinder.

Watch a YouTube video about rear drum brake job, watch the way the hardware goes in, the way to set the self-adjuster cogwheel. The only way you are having the problem you describe is when those parts are sticking or reinstalled the wrong way. You should be able to spot your problem if you compare the good wheel setup on the side you are not having problems with to the bad side setup where the problem is.

Replace brakes recently? What you describe is typical of when the brake shoes/linings are installed in reverse of normal which causes the brake shoes to wrap up and self energize incorrectly. Normally, the shorter of the two shoes should be on the front /forward section of the brake drum location and the longer shoe on the rear but some novices wrongly install them backwards which causes the brakes to self-energize/lock up. That will also prevent the adjuster from working correctly as it relies on the shoes rotating correctly around the anchor point for the mechanism to adjust properly. Check to make sure the brake shoes are installed correctly if a recent brake job was done. Make sure adjusters are in good working order and not set too tight. If one is tighter than the other, it can cause one side to brake before the other and lockup.
Another issue that can cause the drum brakes to lock up is brake fluid or axle fluid/grease on the shoes… Make sure they are clean and no leaks. And also check for a sticky e-brake cable… Over time the metal cables can rust and seize up internally in the sheathing of the cables and not fully disengage. Spray the cable/sheathing down liberally with some rust penetrant spray and let it soak in for a day… Place a tarp or cardboard under the cable areas to catch any excess. Operate the brake handle several times… Full on and full off… And make sure the cables/levers fully release at the brakes.