Sorry to hear of the problem you are having.
Please make sure you are using latest version of theme and plugins.
Have you made any changes using Yellow Pencil plugin?
If yes then please try resetting it as described in the following pages.
If the issue still persists then would you mind if i log in to your site and do some troubleshooting? If this is ok then could you please share me your site log in details privately by adding them in the box having text “Click here to share private content. Only you and forum moderators will be able see it.”?