Cannot reset password due to does not match any of last n passwords requirement
I contacted Apple Support. I was able to reset my password using macOS Utilities in Recovery Mode. 

Boot up holding command+R until the macOS Utilities screen comes up and go to Utilities > Terminal. Type in resetpassword and follow the prompts. I chose the second option, something like 'my password does not log me in' which lets you reset your password if you know the current one. It worked in that reset password function but not the one from the login screen.