White screen with flashing folder

ive had my laptop for two years no problems. Now I turned it on and it went to a white screen then had a flashing folder with a question mark in it. I googled it and I finally was able to start up but only get to the disk utility screen. I verified my disk and itsaid it appears to be ok. What is wrong and where do I go from here!? I cant do anything on it and I'm afraid of losing all of my things:( someone please help!