My website is down?! SOS!

ftp to site or use host’s file manager to rename plugins folder, thus deactivating all plugins
if a plugin is borked this will let you log in

if this doesn’t help, rename your theme folder, thus activating default theme
if a theme error this will let you log in

if neither of these work, try these memory options

1. Try adding this line to your wp-config.php file:
define('WP_MEMORY_LIMIT', '64M');

2. If you have access to your PHP.ini file, change the line in PHP.ini
If your line shows 32M try 64M:
memory_limit = 64M ; Maximum amount of memory a script may consume (64MB)

3. If you don't have access to PHP.ini try adding this to an .htaccess file:
php_value memory_limit 64M

4. Talk to your host.

Thank you very much, Samboll!

It seems the problem was caused when I was trying to edit the theme’s functions.php. Now I have re-uploaded this file.

It is back to work now.

Thank you again for prompt reply! I really appreciate it. *Bow*