Why am I developing violent thoughts and tendencies?

I will start off by saying that I am considering seeing a therapist. The things to figure out are money and time.

I’m really on here only to ask this one question, because this has reached the point where I’m dying for opinions and I cannot comfortably ask my friends or loved ones.

I live with a couple roommates and one of them has a cat. I have owned pets before but never a cat. I treated my pets with love and respect and never once did a thought about harming them come across my mind. I’ve been living with my roommates and the cat for an entire year now.

Gradually, I developed urges to hurt the cat. I don’t want to kill it. I want to torment it. In the beginning, whenever my roommates were away, there was a period when I really wanted to throw the cat in water and watch it flail. I never managed to fully do it, but I did get it really wet several times.

I then had extreme guilt and talked to the cat as if it were a person, apologizing to it and promising it that I would never do that again.

I haven’t thrown the cat in water since, but I have ended up breaking that promise by doing other things. I have stuffed it in drawers. I have stuffed it in bags and suitcases. Sometimes I just pick it up and flail it around in my hands to hear it panic. Just today, before writing this, I poked and prodded it with a stick I found outside. I wanted to force it out of its comfort zone and it mewed mournfully.

The inexplicable urge always comes spontaneously when I’m alone. The bizarre thing is that I want to torment it but then later soothe it and feed it and pamper it. It’s like an abusive relationship, which doesn’t make sense because I’m currently in a relationship and have not abused nor have any desire to abuse my significant other.

I have noticed a general trend in this “inner rage” that has been developing inside of me. When I was little, I always wanted to do good. As I grew up and learned about politics and the “real world”, I developed urges that ruined that “heroic” dream of mine. Instead of my delusions of grandeur being about saving people and feeding the poor, I zoned out to fantasies about mass murdering every single politician on the planet. Every time the news happens to be on (whether it be FOX, CNN, NPR, etc), I get triggered and want to go postal on the entire world. I’m also very high functioning. I could be talking and laughing at dinner but on the inside I’m screaming, “LAY WASTE TO THE ENTIRE PLANET. BRING A NEW GREAT FLOOD. KILL EVERY LIVING CREATURE. MANKIND CANNOT REDEEM ITSELF.”

It drives me to be physically fit. I run and jog so fast for my age because I think to myself “I have to kill Trump” or “I have to kill Hillary.” When I do intense workouts, and if I happen to be alone, I can push myself by shouting aloud, “I’M GOING TO FUCKING KILL YOU, TRUMP.” There are times on the treadmill when I have nearly broken out screaming in rage. I never actually did it, but I was close.

Like I said, it reached the point where I want to do something about this and want to understand why I’m like this. I hate it. I hate it so much. It’s like there’s a demon inside of me constantly croaking, “Kill them. Kill them all.” It’s so much easier to destroy than to create or maintain. I’m worried I’m developing a mental illness. A friend of mine who is a social worker has said that mental illnesses in men can emerge in their twenties and cement by their thirties, even if they showed no signs before then.