I cannot find individual photos to attach to emails or other documents
I have 'upgraded' my iMac to El Capitan. So far it has managed to lose an email account, which I've thankfully managed to retrieve, but now I cannot attach photos to any documents directly from finder. Pictures used to be just images I'd created myself or imported from other devices that didn't go directly into photos. Now Pictures seems to contain iPhoto library and a Photos library, but it won't open them out when I want to find an individual picture to attach. If I click on either library, it will only attach the whole library! All I've been able to do is go into photos (when it's not crashing on me), and save an image to the desktop, and then from there I can attach it to wherever it needs to be. Clearly, this is longwinded and time consuming and frustrating!
Hoping someone out there has a simple fix?!!
iMac, OS X El Capitan (10.11.2)