season-end affective disorder (sad) 

That feeling of inexplicable sadness you get when a TV series or book series ends.

'You haven't been out all week, what's wrong with you??' 'Sorry, Game of Thrones ended last week and I feel like part of me has died' 'oh, you have season-end affective disorder (SAD), I've been there'

season-end affective disorder (sad) by Josee August 1, 2015