iPhone 5s camera won't work at all

My iPhone 5s suddenly stopped working. The camera app will open, but only a black screen appears--nothing from the viewfinder. I can scroll through the options of video, camera, square, slo mo, etc., but the center button to press when taking a pic or starting a video is inoperable as well. I've imported all the pics off my phone, and there's nothing in the deleted folder, but when I plug it into iTunes, it says I have a TON of photos on my phone when in reality there is zero. It sounds like something is internally wrong with apparently having a 'phantom photo folder' now. Any suggestions on how to get the camera working again? I have backed up my phone and reset it, but I do not want to restore to factory settings as I do not want to lose anything else that can't be recovered.

Another note to add: Photos can be sent to me and will store in my camera roll, but still can't my own pics. I've added the camera+ app, but that is unable to take photos as well due to the camera.

Thanks for the help!!