Missing a FaceBook Group and every trace of evr being on it.

A Group I belong to _"Writing In The Dark" - seems to have disappeared from my whole computer.  I notocedit wasn't in my group list on FaceBook. Then I tried to seach for it in the "SEARCH BOX' . It did not come up - cant find it.  I want to my Timeline Page and looked through my "Activity Log" and there is no more traces of it there either.  I re-read my comments from friends from the past 2 days, and nothing written to me involving people from "Writing In The Dark" is no longer there.  Everything imvolving the Group is completely gone and I have no idea why or how to get it back.