When your brushes disappear and you lose your work organising them.

Hi All, 

I've read the posts about where to find brushes after they disappear from Photoshop on startup. That part isn't the problem. I structured my brushes pallate so that certain brushes from certain packs of downloaded brushes were in specific folders which I had named and organised so I could find them. Everything was fine for a few months until today when I rebooted the computer and discovered that the brushes were no longer in my panel. I understand that I can reload them, but I've lost the work I did selecting and organising them into dedicted folders.

Is it just accepted that you will lose your Photoshop brushes randomly? That seems to be what's implied in the other forum posts about this. Why does this happen? Is it a bug, or does Photoshop not want you to use custom brushes? 

How can I save the work I put into structuring the brushes panel so that it doesn't get lost next time this happens? 

I'm running CC on a five year old iMac