i am unable to access my site due to 500 error

If you face this issue don't worry its a very common problem where the server throws an error stating 500 there are many reasons behind this that may be a log file was not given 0777 permission, may be a .htaccess file was not set properly, may be a storage of the server and can be a Ddos attack on the server. if you persist this issue we advice you not to panic about your site or application and to wait some little time until if get rectified or feel free to raise a ticket.