Greetings! This is a rather heavy question that deals with a lot of the consequences of studying so much about humanity's past, and it is definitely something which can prevent some people from studying a certain event or time period in more depth. This previous thread about studying history without becoming a nihilist (with contributions from several travelers, including a few flaired users) might be of some interest. I have copied my own response from there but I have also adapted parts of it to deal with how one can deal with the darker parts of history. Let's begin.

My area of expertise encompasses two of the most brutal, bloody, and terrifying conflicts in the history of our race. In the course of my research I've seen photos of combatants with all innocence gone from their eyes, the atrocities committed by both sides in the pursuit of victory, and the destruction wrought on our planet's own face. In short, I find truth in the words of Arthur Koestler:

"The most persistent sound which reverberates through man’s history is the beating of war drums."

Yet with all these lessons, tragedies, and experiences, for every dark event there is always a brighter one to be found. In the case of the world wars, I'm reassured by the benefit of hindsight and generations of progress. I know now that for each Nazi victory in the early stages, there will be a more decisive Allied one to come. I know that the Treaty of Versailles, as flawed as it was, was written by the just victors of the Great War. I know that despite the horrors of mass genocide and death, there will be an end to the killing and justice shall find its mark.

I also however, gain motivation by asking the simple Socratic question: why? Humans were not bred (as far as I am concerned) to spark destruction and take the lives of their own kind, so war as a whole is a uniquely human phenomenon that has unfortunately plagued the record of civilisations. How did our societies come to blows over the most varied (and at times trivial) of causes? There is always more to be found out about the past in my view, and that is the singular maxim which drives me in my research and writings.

Now on the more preachy side of things, the old cliche of "those who fail to learn history are doomed to repeat it" is not something I stand by. Drawing parallels between events happening now and a century ago is dangerously single-minded in my opinion. The optimism gained in knowing more about the past and keeping that record as an evolving narrative is instead, I believe a better reason for my continued positive outlook on the world.

So all this being said, at the end of the day, I find more truth in Aristotle's quote than Koestlers:

We make war that we may live in peace.

Dealing with the Past

However, the content is so disturbing to me that I no longer approach learning with passion but with a sense of hopelessness. I know this is the wrong attitude, but I can't help that its really taking a toll on my mental wellbeing.

Firstly, please do not feel like this is by any means the "wrong" attitude towards approaching the study of history. As I and countless other AH travelers and students of history can testify, that sense of hopelessness is almost always lurking in the corners of historical narratives.

As for how we deal with the horrors of yesterday, I find it helpful to always keep in mind that there is a bright spot for every tragedy and dark event which has occurred in the 20th century. As such, whenever I do my research and writing on AH, I always make it a goal to be as "neutral" as possible in my tone. u/OppositeRecording551 has already touched on this in their comment, but the general mantra of "connected, but not invested**"** in the past is a good thing to stand by. What I mean by this is that when you're viewing 'heavy' events, persons, and concepts; it's dangerous to get so emotionally attached (or detached, for that matter) that it blinds your own view of that historical topic.

As you no doubt are aware, there is a lot of information about the 20th century's darker aspects, and it can be daunting for a bit. In this instance, I was able to sort of 'sort through' the heavier, emotion-sparking narratives and first focus on the academic narrative of the event. So for example, instead of first focussing on the experience and trauma of shell-shocked soldiers during the First World War, I familiarise myself with the reasons why they were fighting in such conditions in the first place, and how their experiences have helped shape developments in technology and medicine. It's always nice to supplement your own research by doing a bit of side-investigating into the positive impacts (or indeed the commemoration/memorialisation) of those tragedies.

Hope this helped a bit, and feel free to pm me should you have any follow-up questions or just want to seek help on treating a 20th century topic with emotionally-taxing elements.

I will also have to apologize if this response breaks a rule on this server, as I am new. History, especially European history, can be incredibly dark. Learning about the injustices and trauma others have experienced, especially back to back in a lesson, can make things seem hopeless. A part of that, I argue, can be traced to "empathy fatigue." According to the Cleveland Clinic, it is common among healthcare workers and those interacting and advocating for people on a regular basis and coming into contact with others trauma. It can lead to a whole host of problems, one of which, a sense of hopelessness, seems to fit your situation. I have heard it described, in a psychology today article by Neel Burton on Empathy, as the emotional response to trauma, where the individual feeling it takes the pain of another and tries to imagine that pain inflicted on themselves or inflicts some emotional pain on themselves.

That lack of control and seemingly endless train of "dark" history, unless held at some distance emotionally, will make learning difficult. Compassion, explained in that same article, is more akin to trying to take the burden and pain off another's shoulders instead of trying to feel it for oneself, although understanding that weight, or being empathetic, can lead a person to be compassionate. Compassion then, is more active, and while historians cannot undo the past or help every individual, they can do their best to examine and learn about history with compassion and a degree of objectiveness. While that is not exactly comparable to say a nurse, doctor, or police officer dealing with trauma, I have found it useful to keep a compassionate yet distant mind while learning about our past, and it has helped me keep a clear head and take care in understanding the emotions, perspectives, and factors behind historical events.

It comes with the job.

Sometime, being deeply focused on historical events that are dark and involve a lot of dead and suffering, it can happen that I become 'immune' to it, as it just becomes figures and numbers. Rather dark, I remember the quote from Stalin:

"One death is a tragedy. A million death is statistics."

Over time, this sort of becomes reality for me. You know you are in deep when you are plotting in victims of rape, murder and mutilation into a spreadsheet, as it were your taxes. The descriptions can be hard though, as vivid descriptions seems like some horror movie script and then I have to remember, that this actually happened. Sometimes I also set it up against other descriptions and sources and i become rather apathetic about it.

That's not to say that I am cold, because sometimes even the endless figures and descriptions can affect me in ways that I'm not aware of and this comes out in different ways.

I did an essay about the Askari soldiers in German service during World War 1 and I was reading about the rather horrible conditions they were facing during that time.

After a while, I found a source describing how there was a ceremony for those who had fallen. During the ceremony, the psalm 'Ein Feste Burg ist under Gott' was song. Out of curiosity i looked it up. While listening to it, I just stated crying as the months of statistics and sources suddenly became 'real' to me.