I can't change my skin

I bought minecraft and started playing just a few days ago. I downloaded my custom skin on planetminecraft(if this fact helps). I can't change my skin. I've tried changing it in the launcher. The launcher says that I'm already wearing the custom skin.

But my in-game character is always stuck at Zuri for some reason.

I've tried changing it from minecraft.net and it says that I'm already wearing my custom skin.

But nope! It's still Zuri in the game. Even when I tried to change it to one of the default skins other than Zuri (Steve for example).

But it's still Zuri in the game!

I know that my issue might have to do something with this bug which tells me to remove any incompatible software or malware on my PC. I've done that. I used AdwCleaner and Malwarebytes to clean my PC. I deleted every incompatible software they listed. Even after doing all that, it still doesn't solve my problems. My in-game character is STILL Zuri. So, mods, please don't delete my post and redirect me to this bug. I've tried it and it doesn't help at all.

This problem seems to affect every version. I installed older versions but my character is still Zuri or Steve. I've tried every option available and yet I still can't change my skin. I'm out of options. Please help.