Help ! Photos disappearing in front of my eyes !!

I hope someone can help, I'm also trying to get hold of Adobe. This is the second big issue I've had within the last few weeks it's so so frustrating ! 

when I'm in lightroom photos are literally disappearing in front of my eyes, the albums are disappearing too. I can see the count on 'all photos' ans it's just going down and down, when I try and find certain photos they have completely vanished. I've kept raw images on my passport and when I reimported an album last time me edited photos reappeared. What is happening?! I've gone on to lightroom today and a whole wedding has vanished and the number of photos is lower again. I can re import them but I've very nervous any of the edited ones have been lost for good that i hadn't yet exported. Why does this keep happening? 

I also am holding off on the upgrade, when I upgraded last time my whole account stopped working and they had to switch me back to the previous version for now.