Tried all previous duplicates to my issue, none worked. Cant see mine nor other's skins, and only can open game using optifine

Okay, I have looked everywhere. I have tried all the fixes that I could find. I am unable to open the latest snapshot, just says that the game stopped responding. I can open the game via OptiFine (to be exact this: 1.16.1-Optifine_HD_U_G2), but only after I've forced it to stop using task manager. Literally click force stop on it and then it loads.

I also am unable to see my skin or other's, again I have tried all the other fixes said on here and none have worked. Been this way for about a month or so, I even asked my tech friend and he couldn't figure it out. I have tried uninstalling Minecraft fully, then reinstalling it fully. I have tried switching between my skin and Alex/Steve on the launcher and on the minecraft.net website, I even tried deleting everything in the skin folder, and it no longer has anything in it. I even tried just putting my skin in there for a second to see if it would help, still nothing. (Like I left it in there, loaded up the game then checked and nothing!)

I do not have any malware that is incompatible. All the servers I'm on (at least to my knowledge since none of my friends have similar issues) are on online mode. I am connected to my own home Wi-Fi even. I seriously do not know what to do or how to fix this, please help me.