I deleted my admin account by accident now my password is not accepted

Do you want to create a new admin account?

That can be done by removing a file that will cause 'setup assistant' to re-run. All your apps & data will stay intact, but you get the chance to make a new admin user.

This is a simple process, but involves some potentially dangerous actions, please read all of the message before trying anything…

Boot into single user mode by holding cmd+s at startup.

Eventually a command prompt will appear and you can begin by entering the next 4 lines, do not include the line numbers.

fsck -fy /
mount -uw /
rm /var/db/.AppleSetupDone
reboot

Setup will run, reate a new user account (give it a new name, do not reuse the old admin name). This account will be an admin that can address whatever issues you created when the old one was damaged/ deleted.

If you have no backups & want to make one before beginning please ask, it should be safe if done correctly, but mistakes within single user mode can be costly - you have access to the entire system with no undo.

If yo get any errors record them (possibly a photo) & post them here.