Upfront isn't working, just get a white screen


I have a problem with my site. I was working in upfront yesterday and I had a glitch - a component stuck to the mouse and wouldn't stay static on the page, so I hit f5 to refresh my window & now I just get a white page so I cant physically do anything. This glitch happened a few times before and I did the same to get out of it but this is the first time the white screen happened. Please can you help?

I have tried disabling and re-enabling the theme, and I have cleared all my web cache temp data with ccleaner to see if it makes a difference but no luck.