A document that I've typed has disappeared. Instead I get the same page over and over again, and there is a red arrown threequarters of the way down. HELP!

I have a long document that I've been working on. When I opened it today it had disappeared. When I tried again it was there, but it was only one page and it was printed over and over again. There is also a RED ARROW three quarters of the way down each page. I think I need to get rid of this arrow. Problem is, I don't know how. Please help as I've spent hours on this document.
Thanks! I have just noticed that on each page there is a few lines of one of the other pages.