The reason for the error should be visible in the error log. You can find it in your hosting area. If necessary, the support of your hosting can help you.
Alternatively, you could also enable debugging in WordPress. How to do this is described here: https://wordpress.org/support/article/debugging-in-wordpress/ – also here the support of your hosting can help you if necessary to edit the file accordingly.
In both cases you should be able to see what the cause is in the logfile. Often it is a plugin. You can delete the directory of the guilty plugin via FTP. After that you should be able to access it again.
Where do I find my hosting area
Please contact hostgator support.
You will need to contact your hoster’s support for this. According to what I see, you must be with Hostgator. Their support can be reached here: https://www.hostgator.com/contact
