Website is down due to change in active plugin

Hello,

I made a big mistake. My website’s Instagram plugin wasn’t updating the feed anymore so i went in the admin board to edit plugins and make sure everything was in order. I forgot the plugin was actived and i tried to change “username” by my name and saved the changes. Since then, my website is a white page and I can’t even access my wordpress admin board anymore.. I realized it quite quickly and asked to go back in changes but nothing happened..

I haven’t make a back up :S I hope someone can help me to figure this out?
Would be really much appreciated!!

I know i havent upgraded yet the new WordPress version but I am not certain on which page I am… Best alexandra

The page I need help with: [log in to see the link]