Help help - all photos and videos gone

[tinkskfa]

Help please, phone run out of battery and put it in to charge and noticed all my photos and videos gone???? Haven't touched or done anything to it although the memory is full nearly as though they are still on there somewhere but hidden as my apps don't add up to the amount of memory used. The photo on my phone is still there and that was in my gallery too. I have plugged into my tablet but still not there either.........help