Everything seems broken since failed uupdate to WordPress

Hi,

My business website went down after a WordPress update failed; apparently I’m now on 3.6.1.

Before the update, everything worked fine – I merely updated for security reasons (ie to avoid hacks etc). After the update, some content present in WP-Admin stopped showing on the website anymore, and some pages merely displayed.

I couldn’t even access WP-Admin, so I restored files from a recent backup and restored access; all recent content is there but some content and pages are still missing from website. I’ve also restored from a recent database backup but – no change.

In fact, on some pages, simply pressing View Page in WP-Admin will result in a 404 error.

I’m also now struggling with Wordfence plugin, which continually displays an alert about not being activated. It was before the update and when I attempt to activate it, a message says that it is already activated.

From my summary, can this be fixed?

All I want is for the content in WP-Admin to be displayed on the website, correctly formatted (as it used to be) and for plugins to stop moaning about not being activated.

Please can someone guide me though what needs to be done; the web developer I used to create the site in August 2013 no longer deals with WordPress (so won’t help) and I understand so little about WordPress.

Thanks in advance,

J (very desperate – it seems like the end of the world).