I really think you should get some help from someone in hosting to check everything is right as far as file permissions, .htaccess file is concerned. Just show them errors and they may be familiar with this issue to resolve it quickly.

You don’t need to change your database (at least not now). Once reinstalled, you need to change the wp-config.php to point to the same database and hopefully the problem will be resolved. Since the options data resides in the database and you should not be losing the options.

No need to change the wp-content directory now and hence you won’t lose the any customized code. Pls make sure you deactivate all plugins before you reinstall. Thanks.