I'm writing a paper about the Thirty Years' War and it's exceedingly depressing. It's actually affecting my mood, so I have to take breaks to cheer myself up. What has ever affected you like this?
My main areas of study have been Pius XII during WWII (basically his actions regarding the Holocaust) and the Spanish Civil War. In both subjects senseless death is ubiquitous. There's also unrelenting partisanship by a large number of the authors involved (worse with Pius XII than the Spanish Civil War). And everybody has an opinion on these subjects, as well as an opinion on my opinion (or what they imagine my opinion to be). I have certainly felt what you are feeling. If I could will myself to be fascinated with something else, I would--but passion is passion.