Help! Pictures gone after update!

[sumeda]

I updated my phone sometime last week (I think maybe Thursday?) and just now noticed that all my pictures from before are missing. I had an SD card from an older phone and it is installed in my S4. It did transfer over my pictures from my other phone and it was all fine until I got the recent update. Now all I have are the pictures from last Friday, after the update. I have plugged in my phone to my computer and looked in the DCIM folder but the only pictures there are from Friday. Is there any way to get back all my other photos from my old SD card, or were they deleted? What happened to my other photos? Also, I don't know if this is relevant, but my lock screen photo is still showing, but it is one of the deleted photos.