My iPhone 5S won't show up in iTunes to sync. It charges still and it opens iPhoto, but doesn't even register in iTunes

My iPhone 5S won't show up in iTunes to sync. It charges still and it opens iPhoto, but doesn't even register in iTunes. I have no idea what to do and nothing is working!

And the other night while i was trying to sync my phone, it was working until "Error message (-50)" started coming up every time i tried to sync or update my phone's software through itunes on my computer. eventually, itunes quit and i unplugged my phone and updated it wirelessly. i have no idea why any of this is happenings. Itunes is still acting weird for me too.