Q: I just updated my ipod and now everything appears to have disappeared and there is only a picture of a USB plug on the screen. My computer is telling me I have to reset it back to factory settings. Should I do this or will I lose everything?

can someone help? I just tried to update my ipod touch to ios 6 (I think) and now everything has disappeared from my ipod and there is just a picture of a USB plug on the screen and my computer is telling me I have to reset the ipod to factory settings. Should I do this and will I lose everything?? Help, I use this for teaching every day.