If you have access to cPanel, you can get inside of and *carefully* alter your WordPress installation by that means. But first things first, all right?
Let's see if we cannot get some more detailed information with the WordPress debugger, before we start taking any action.
When you go into your cPanel, do you have a File Manager icon/link?
If so, open that and find a file called wp-config.php. There is one line and only one line you should alter.
Please change this: define('WP_DEBUG', false);
To this: define('WP_DEBUG', true);
Save the change, and then IN ANOTHER TAB OR WINDOW, try to visit your website. It will not be fixed, but there will most likely be an error message-- possibly more than one. Copy and paste the error message(s) for safe keeping, so you can post it back here later.
Almost done. Now go back to the wp-config.php file and change the true value back to false again, and save the file. We are returning the wp-config.php back to its original condition, in other words.
Then, if you'd be so kind as to share the error message(s) with us, we can better advise you how to proceed in repairing things.