I am the person that will be helping you today.
Is this regarding a cell phone? If so, may I ask for the brand and model name of the cell phone?
I will be standing by, looking forward to your response.
Do you know what may have caused the problem? Did you update any software recently or reset anything? Please, turn your phone all the way off, remove the mini SD card, re-insert the card, and turn it on. Are the items still missing?
Please, take a picture with your camera. After doing so, look at your gallery. How many pictures do you see there?
Turn the phone off, remove the micro sd card, turn the phone back on without the card in it. When you go to the gallery with the card out, can you still see that one picture or is it now empty?
That is great to hear because that means that the images and music are not lost. Do you by chance have a micro SD card reader so you can make a backup of the files on it before we begin? It's always a good idea to have a backup just to be safe. After making the backup, I would suggest first removing the micro SD card and then resetting the phone back to system defaults. Doing so will erase everything on the phone and the possible faulted settings. You reset the phone as such by Tapping the Apps > Settings icon, choosing "Factory Default / Delete settings", and allowing the reset. After it is reset, put the micro SD card back in the phone, turn it on, and report back.
I am not talking about your SIM card. I am referring to the micro SD card, which is the card that stores the photos. If the micro SD card in the phone is faulting, it would be a good idea to purchase a replacement micro SD card. They sell micro SD cards at all stores that sell cell phones and computer items (ie: Walmart, Target, etc).
Please, let me know if you need anything else.