Hi,
Method 1
Open Filezilla.
Use FTP.
Within wp-content, in plugins folder, you will see wordfence plugin.
Delete this wordfence folder. Now you can login.
OR
Method 2
If you have access to your site's cpanel, login to cpanel.
Use filemanager.
You will see wordfence folder in plugins within wp-content folder.
Delete wordfence.
When you reactivate wordfence keep login attempts at 5.
This should solve your problem.
Best wishes,
Ashok Koparday