I've had this happen myself a few times. Then my SD card got mostly corrupted, but it wasn't new, I had a 64GB Kingston Class 10 SD Card that I've abused and over used for the last few years coming from my Epic Touch 4G (Galaxy S2), Galaxy S3, and now LG G3.
My best advice:
ALWAYS backup your SD card every three months onto a computer and external hard drive, and replace your external hard drive and SD every three years if you're a heavy user (just to be safe).
I installed a newer 32GB Sandisk Class 10 (until I replace my 64GB card some day) and I have not once had it "eject" at all since. So that's probably heads up that your card is failing. Whatever you do, don't format it and keep using it, it's on it's way out from the sounds of it. The thick bars/lines in the photos are a good warning. Buy a new one as soon as you can, for now try to stick to internal storage.