My iphone 6 won't turn on, it is just black. It says to updated it (I have the IOS 8). I connected to itunes but it won't update, it says to restore it BUT I cannot not loose all my data (not everything is on icloud) Any suggestions?

My iphone 6 (IOS8 64 GB) won't turn on. I have not done any updates to it since the IOS8 but everything seem to work until few hours ago. I was recording a video and it just turned off. I tried turning it on pressing the power button and the home button, but it did not worked. I connected to itunes on my computer and it says something is wrong with the phone and that it needs an update and that if does not work I might need to restore to factory settings. Unfortunately, the update was not possible, I ignore the reason. I do not want to restore it because the last backup was before coming abroad, so this means that all the pictures (museums, historical sites, etc) that are not on icloud will be lost.

I really do not want this to happen, help PLEASE!!

Is there anything I can do? Or should i wait to take it to an apple store?