I keep doing this to myself.

That's called Post-Traumatic Stress Disorder and by all means it's rightful for you to feel like that.

If you haven't seek out for psychological help, it might be a good time to reach for a professional.
I don't know what techniques are used to handle other people's traumas, but if I might be able to help you just by talking, then by all means feel free to reach out to me.

If I may suggest something that has helped me personally with my traumas, is that I occupy mi mind into learning something new.
I used to study languages. I learned a bit of Japanese (gave up on Kanjis) I learned French, a bit of Portuguese and Russian.
I also used drawing as a way to keep my mind occupied and I also exercised a lot back in the day.

Also, be aware that these problems occurs when there's a misadjustment in hormones, maybe chemicals in the brain such as Dopamine, Serotonine, Endorfine, Adrenaline, and some more.

Personally, I believe that everything I feel mentally has a chemical cause in the brain. Sleeping well, keeping me entertained/occupied and physical exercise often helps A LOT. But that's just me and still think you should try to reach out for a professional. You just can't live like this you know?

I am restricting your Netflix

Thank you all.

And to @WG481 waaaaaaah (secretly went and subscribed to HBO)

Hi. I am sorry to hear this. Let me write a few words if you don't mind.
These traumas, sometimes repeated over time, are very difficult to eradicate, especially if you have the tendency, the habit, of periodically replaying them in your mind, and making them more and more stable.
What our Juan suggests about a psychological therapy (psychoanalytic) may be a way to go, perhaps the most obvious, but personally I do not believe in its effectiveness.
The psychologist would prescribe tranquillizers that would only apparently solve the problem, and even talking can apparently alleviate the pain, but in the long run returning to the past with the memory of it only stabilizes, reinforces the traumatic memory and the tendency to imagination. I don't know a single person who has been definitively cured by a psychologist/psychoanalyst: after years and years they still go there, and their problems are still the same.

As Juan rightly suggests, and here I agree more, do something that promotes discipline, concentration such as studying a language, studying mathematics (for those who like it), painting, solving puzzles, even playing videogames (not the war ones, I recommend), etc.
And here I add, not by chance, my explanation and the nutshell of my speech. Very often we return with the mind on old memories, also very unpleasant:
1) because to them are linked by association also pleasant moments;
1) because over the years they have become stronger and have become a habit, a fixation, an obsession.
There is a part of us that would like to forget them because we suffer from them, but another part of us feels pleasure in contemplating them from far away in time and space, now safe (like when you hear a strong thunderstorm, but you are safe in our bed).
Watching war movies and then crying in remembering only confirms this tendency.
The real solution, which is very difficult and requires great discipline and determination, is to break this chain of memories and habits in the bud, at the moment of the decline of attention and the birth of the first mental image related to the trauma.
And it is often after a strong disappointment, an argument and consequent depression, or after drinking alcohol that the first image arises.
This is why I reiterate the importance of always being lucid, attentive, concentrated and aware, in all areas of life, so that the tendency to imagine does not get the upper hand.
I would recommend, to you as to all, the practice, daily and forever, of what you Americans call "mindfullness": in everything you do, small or big things, maintain self-mastery, attention, mental presence, full awareness of the here and now.
Whenever an image from the past, an imagination or a daydream arises, drop it and return to the here and now.
And then learn to think only when really necessary, for practical and concrete reasons, avoiding inner dialogue and mental brooding.
To many this will seem an impossible and useless task, but it is not, and if practiced with perseverance and determination, in the long run, it will solve all the emotional problems, obsessions, phobias, compulsions
going to the root of the problem, the tendency of the mind to imagine and dream.
To achieve this it would be necessary to practice meditation, as taught in the East, but I do not think you are interested in practicing it, many do not have the necessary patience, they despise it and underestimate its benefits. In the unlikely event that you are interested, I am ready to give you some advice. Otherwise, follow Juan's common sense suggestions and consult a psychologist, who will prescribe you anxiolytics and practice the talking cure, making you relive old wounds again and again and thus reaffirm them.
Sorry if I went on and on, and forgive my bad english.