Why have I lost my photos when I updated my Lumia 800 to Windows Phone 7.8?

[Windows Central Question]

After being some time with a Lumia 535, I thought I had the Lumia 800 stopped in my bedside table! Then I went trough it and I updated it to the Windows Phone 7.8! I went to the pictures library and the photos weren't there! I had the OneDrive (SkyDrive in this case) off and, well, I lost everything... I know the images are still there because the space is still being occuped... HELP ME FINDING THOSE OLD MEMORIES! PLZ