Am I guilty or is this a toxic family relationship?

I (18M) have grown up living mostly with my mom and dad. Both of them work very hard (from 8:30AM to 5PM) and come home pretty late (at 6PM usually because they do shopping as well, not everyday).

I have an older brother who is 27 currently and lives and works 200km away from our home town. Sometimes I wish he was here to support me, because often I am so stressed by my parents who always argue and fight.

My mom usually comes home very tired and suddenly starts picking fights with me or with my dad. I don't pay much attention to her when she tries to argue over small things, and I just continue to mind my business.

But the fights that my mom picks with my dad are completely different.

Dad's side of family is a part that mom doesn't stand(grandma, aunt, uncle and cousin). She often begins to randomly pick on them (not directly in their face) in front of my dad. This is something that annoys my father very much pretty often, but sometimes he makes an exception and doesn't pay too much attention.

Even if he tries to ignore it, mom just continues to talk about them in an offensive way.

When dad talks with his mom or sister, my mom begins to annoy him by talking like I mentioned before. It annoys me too, but not that much as I am already used to it.

She also doesn't like to pay them visits and she doesn't like them paying a visit to our home either.

As my dad became less and less patient over the time, he becomes irritated very easily, even over small things(he is 54 currently, while mom is 56).

This gives me an example of how NOT to be as a father, if I ever happen to become one.

Nowadays, he started becoming more and more aggressive when irritated because of mom's words. He started threatening her with a slap or random things thrown at her, but he never does it actually, at least not yet. He insults her, and she begins to tell him that he's crazy, even though she began the argument.

After a few minutes, the fight calms down or ends completely, but this is something repetitive that I have to hear, see and suffer a few times a week.

Now talking about me, I admit I am pretty undisciplined. I don't study as much as I used to do 2-3 or maybe 4 years ago. I am addicted to screens and video games. I also keep daydreaming about a girl that I have a crush on but I never tried talking to her. Although I am lazy most of the days, I have some ambitions, like going to the gym and building an aesthetic body, developing a phone app that I keep on working, or learning cybersecurity or even the German language.

Although I have these ambitions, I don't always commit to them. That's why my parents tell me that I am a lazy piece of shit, an idiot or a donkey, because since I am 18 I haven't moved a single toothpick or done anything good.

I want to move out of this home. I want to live with my brother and study in that same city. Or at least do something about this family issue. I just can't help it but sometimes cry alone in silence in my bed in the evenings. It's just too much. I wouldn't want to run away from home, but if I can't stand it anymore, I'll do it.

Please help me with some honest advice...