You should be able to access FTP by signing into your web hosting page.
cI copied this for you, i once experience similar problem.
Original creator @wbcomdesigns
Try MANUALLY Disabling the plugins
To do this, you will need access to your website’s filesystem through your control panel’s file manager, FTP or direct shell access via SSH. Follow these steps:
Navigate to /wp-content/plugins
Find the directory/folder of the plugin causing the problem
Rename the folder (pirate-forms)
You should now be able to login to WordPress, and you will receive a small error message indicating that the plugin failed to load.
Hope this will help.
Thanks.
