Photos are gone

Time Machine storage showed full. Not sure what button was pressed, but a process began that I couldn't stop. All photos, events etc are now gone from iPhoto. When I open the timeline in backup, there is nothing there aside from "now". All other windows behind it have nothing. HELP!! (The pictures are all still on my apple TV ... can I get them back from there?) No other files on the computer (documents, etc) seem to be affected.