Hello Katie,

first thing is welcome to the EU. ;-)

secondly regarding your accommodation in Flatshare in London , I can tell you that there are different webpages in Internet where you can find information or book a room.
For example I recommend you this website http://www.studios92.com.
Another website I have found is http://www.uklodging.com

In these two ones there are offers of hotels and hostels as well. A website however which only offers Flatshares is http://www.flat-share.com.

I hope to have helped you. Anyway you can consult the small ad section for offers or put your own request on there.