WordPress and woo commerce suddenly not working (locked out)

So today i was finishing up the last bits of my website I’v been working on for some time (www.storiesinaframe.com). As it is an online store, I’ve got WooCommerce installed. Suddenly though, the cart stopped working. I tried to change back some settings to see if that would fix it, but nothing helped.
I read somewhere that being logged in as admin on your website could cause this error, so i tried to log out and see if the cart would work now (which it didn’t). When i tried to log back in the /wp-admin wouldn’t load anymore.

Also worth mentioning: I’ve looked trough the root directory to see if there were any changes but i couldn’t find any. Earlier today I tried to change the favicon (without success, since I’m as you may have noticed not all that experienced with WordPress) but as I’m not new to programming, i knew i shouldn’t touch anything. I have tried my best at undoing everything in the root directory, and I’ve read through it several times to look for any changes. I suspect there might be some little bug somewhere in the root directory causing this, or that there is some bug in the new 2.2.2 update.

I use one.com the host and except woo commerce i only have metaslider and woo commerce colors installed (I’m quite sure, can’t check though, since you know, i can’t get in anymore).