Safe mode just runs the phone without the apps you've installed. Once it's out of safe mode, all the apps you've installed are available again.
Safe mode has nothing to do with your photos. If safe mode deleted your pictures, there's something wrong. If it's still under warranty, bring it in for repair or replacement (their choice).
Of course since you back up all the apps and photos you don't want to lose, it's just an annoyance, not a tragedy.