Fatal Error memory size exhausted 134217728 bytes

Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 125 bytes) in /home/ironindi/public_html/cms/wp-includes/option.php on line 149
This has crashed my site I have no way of reaching Dasboard although the site is still running I have no means of repairing or altering to fix it, I’m a newbie to this so any help would be appreciated and in laymans terms please , lately it has been having errors when putting on blogs or downloading photos from media library and slow doing these operations