Flashing folder with question mark on start up - Can't repair

After some urgent advice!

All of a sudden on start up of my macbook pro I've started getting a flashing folder appear with a question mark. Upon doing some reading and research, it appears the reason it due to my macbook not being able to find the system software? I've read through all the suggestions Apple has given such as internet recovery and doing a repair, but either the options are completely greyed out for me, or it can't find my disk utility.

Does anybody know if there is something I have missed? My macbook is only 3 and a half years old so can't quite understand why it seems to have died. Does it need a new hard drive perhaps?

Thanks.