Database Error

Yesterday everything was working fine. Starting today when I tried to make a post to my blog, all it did was save it as a draft. I cannot move the draft to trash. It says it’s been moved to trash when I do it, but it’s still there. I cannot publish the post. It says it’s published when I click the button, but it’s really not. I cannot switch themes, it says “theme switched” when I hit the button, but it never actually switches, I can keep hitting the “switch” button and it will keep not switching but saying it has. I cannot deactivate/activate, or delete plugins. It says “plugin deactivated”, “plugin deleted”, but they’re still there. I’ve uploaded clean versions of wp-admin, I’ve “reset the plugins folder” via FTP, I’ve tried switching themes and deactivating plugins (doesn’t work). Can anyone please help? I have the MailPoet plugin (was working fine) and just after these problems started happening I tried to edit one of my newsletters, and I got this error:

WordPress database error: [The MySQL server is running with the --read-only option so it cannot execute this statement] UPDATE wp_x8zry6qgds_options SET option_value = 'a:0:{}' WHERE option_name = 'wysija_msg'

Really hoping someone can help me out, I can’t do anything with my site!