AITA Brother Disagreement

Ok so im not trying to make this story long so Ill try to make it as short as possible.

My brother brings me to live in Orlando, gets me a job, accomodates the purchase of a Porsche, later on an Acura is purchased for him but under my name, so its technically my car as well. The job he brought me to fired me, went a month unemployed. Got a job, now im catching up on everything of the past month. Gotta make car payments for that juicy porsche, all in all, im driving the Acura, hes driving the porsche. Whenever we bring the topic of the cars it gets heated quick, cuz hes shortfused. Then everything comes alight. Rent, groceries, gas, even soap for washing clothes. He threatens me to kick me out or whatever and im just catching up on everything I owed.

Im a slow to start guy when it comes to fighting, he just blows a fuse and goes at it. Hes my big brother so I dont want to fight him cuz we are gonna fuck each other up heavily. But he keeps testing me all the fucking time. We had a disagreement that started with a dog whining, then it lead to groceries, then car payments then physicality by his part. I was ready to swing at him with a watch, but I backed down, I wouldnt do harm to my brother like that. I called him out cuz im respecting that one line you dont cross and its getting physical with your bro, but then again hes not respecting it, why should I? AITA for calling him out when hes wrong and wont admit to it? Just defers to another problem? Like fuck me man

Breakdown of the actual disagreement

I get home and the dog starts whining for my attention, but my brother doesnt want the dog out his cage so I just ignore it. I go to my bed and he keeps whining. My brothers pissed at the dog so he smacks it a couple times so it could shut up, but it didnt. This happened three times. I decided that I was not gonna sleep and go to the kitchen to get something to eat and sit at the table. The dog isnt quiet so he comes out again. He starts blaming me that the dog is whining cuz I take him out of the cage. He says that I should walk him because im not doing anything. Then I said that wasnt fair because I was working from 5-12 to work again from 6 am to 2 pm. Why do I gotta do it? You had time too! Then all of a sudden he mentions groceries (that I ate all the groceries and that I should buy some). I stay quiet cuz he is right. I walk the dog and I cant resist to text him that he should get rid of the dog. I also text him that if he wants me to buy groceries Ill only make half the car payment. (Honestly that was a dick comment from my part, but still) Im not the only one living in the house. He gets heated and comes into my room all riled up wanting to fight. Im not ready yet so im hesitating alot. In all of this im just telling him im not gonna fight him, but then I reached for my watch. I think he saw that so he backed down and talked to me. We talked things out, but now im riled up and hes asleep. Note that I work at 6 am