Have you tried removed and adding back your google account onto the phone? Remember you can save up to 250 contacts onto your sim card and your pictures to an sd card if you have one. Also if you are registered at att.com and have already downloaded the MyAT&T app you can download AT&T locker and upload your pictures. My best advice is to perform a Master reset and try it again. If not try check your google account settings. Here is a page that will help you https://support.google.com/
*I am an AT&T employee and the postings on this site are my own and don't necessarily represent AT&T's position, strategies or opinions.