I greatly enjoy songs where the subject is losing or lost hope, like Imagine Dragon's 'Monster' although, I can feel the pull from that one, so I do not listen unless I am really feeling broken.
I enjoy reading dark, some would say morbid fantasy. you know, people die, it is violent, some is tecnically for adults, They often involve more than proper romantic scenes, the characters lose hope, lose family, are broken. look it up.
Is it wrong? sometimes I notice it dragging me toward the hole, sometimes I dont care, honestly, it is beautiful, and anything is better than porn. my feeling are at war over wheter it is a negative influence or not.
My take on this may be less popular, but mine comes from a place of depression. So my view is different.
I get the pull towards dark things. I experience it myself, still. And I sometimes question myself on it, wondering if it's a negative thing.
I believe it is a balance issue. We live in a dark world, surrounded by all sorts of evil. Depressed people seem to be more in tune with this feeling. Also more in tune with their emotions. Higher rates of empathy and sympathy can also occur. All of this, of course depends on the level of depression. Some become so depressed they grow numb.
As we read through the bible we see all sorts of displays of feelings and emotions. Positive and negative.
Anger for example. Anger can be a good or bad emotion. It's good when you stay in control of it and perhaps even use it to motivate yourself to do something good with it. Even God has righteous anger.
Obviously bad anger is when it controls you or you use it for evil. Domestic abuse, for example. Or if you're always angry it can have an affect on your physical and mental health.
Even in the OT there's lots of violence. I believe the book of Nahum is the most violent book in the bible. And we see in the OT God sending out armies to conquer other nations. The battle of Armageddon is a violent war.
Now these were not intended as entertainment, but rather history (or the future), but God did not exclude these moments from the bible because of it.
My personal rule on it is no violence for violence sake. Meaning an action movie, for example, has people fighting each other for a goal. The focus isn't the violence, but rather the violence moves the story forward.
Whereas a movie such as Saw, where violence is the real entertainment, I won't touch.
Bottom line life as a Christian is a journey. And everyone's experiences are for them, that God chooses to put them through, or sometimes we put ourselves through and God has to use it to reach us.
Don't feel pressured to change a million things about yourself all at once because others say you shouldn't be struggling.
In regards to your question, personally I find darker themes to be therapeutic, up to a point. Pretending it doesn't exist is nothing more than hiding. And that will only make things worse.
Instead be cautious of how and how much and how often you expose yourself to these things. Going too far will have an adverse affect and make you worse.
And you're right, some things do have a noticeable affect in a bad way. That should be avoided.
Also you'll need to ensure you're not being influenced by anything. If reading something violent starts giving you feelings of being violent, then be aware and cut it off.
I am not a violent person by nature. So I was never affected by violent things.
So pray and listen to God to guide you away from bad things. Educate yourself on why you may be drawn to these things.
Ecclesiastes 6:1
I have seen another evil under the sun, and it weighs heavily on mankind