Thanks for the advice everyone. Have tried everything mentioned above, to no avail. Here is a picture of what the screen looks like:
I've just realised I have no idea what I'm doing when adding photos. Sorry if that's wrong. And I know it's sideways!
Nothing I do can get it to move from this state. The little light flashed blue at me for a while when trying the factory resets, but nothing happened on the screen.
I can't imagine how I've broken it. It was fine when I put it down on the 23rd, then this...!
Thanks for your help.