We're going to boot your Mac to a special mode called Single User Mode. Then type some commands/texts there which will force your Mac to bring the new account setup screen. So you can setup a brand new admin account and then use that account to reset the password ***** your original account. This might seem a little difficult, but it is actually easy.
Follow the steps below to create a new User Account in Single User Mode.
• Turn off/shut down your Mac.
• Turn it on and immediately hold down the Command(Apple) and S keys together for 10 seconds to boot into Single User Mode
• When you see the text prompt, type in the following terminal commands to create a brand new Administrator account (hitting return after each line). Also, note down the spaces between the commands, like a space between mount and -, space between -uw and / etc
mount -uw /
shutdown -h now
(If it returns any errors, then you are entering the commands incorrectly. Make sure you enter it correctly)
When you enter last command and press return, the Mac will shut down. So turn it back on and it will bring welcome screen. Then you should be able to create a brand new Administrator account (when creating the account, if you're asked to transfer information, select Don't transfer). Don't sign in to Apple ID either if asked.
Login to new account. Then in new account (which will be blank), go to System Preferences > Accounts or Users & Groups, select your old account and change/reset the password. Let me know once you did that