I don't know where to put this and just need to let my feelings out.

This summer has been the worst one of my life. My dad and my sister and I agreed that we would spend the summer with my mom (who has just recently began coming around again) so that he could build a house for us. He said it would be done by the end of July at the latest. He knows how bad it is at my mom's (my mom and my stepdad constantly scream at each other, they've started hitting each other, and my mom blows all of her money on pot and pills) so he was supposed to get the house done as quickly as possible. He went the first month and a half of the summer without a job so that postponed the plans A LOT.

I got a job here at my mom's so I could have some of my own money. I'm seventeen so it's reasonable that I have a job. My sister is 18, graduated, has never had a job, and isn't going to college. I take my high school classes along with two college classes AND I work so I'm extremely busy and run low on time. My sister is supposed to keep the room we share clean and in return, I buy her stuff she wants since she doesn't do anything during the day anyway.

My dad just called me and asked what I was doing and I told him I was busy with AP schoolwork and didn't really have time to talk, and he proceeds to start yelling at me because apparently my sister called him and told him I wouldn't buy her this comic book thing she wanted (that was 30 freaking dollars and I'm down to only $75 until I get paid again) and she hasn't done anything on our room in the past two weeks. I've done all of the cleaning.

He told me I need to be easier on her because she's "going through a lot right now". He refuses to call her out on any of her bullshit and on top of that, he told me that being at my mom's has "damn near ruined me" and acts like it's MY fault.

To top it all off, my mom has began making rude comments about my dad constantly. It's offensive because HE'S the one that raised me. Not her. She has no right to talk about his decisions.

I just feel like I have nobody to talk to here. All of my friends, my family, and my boyfriend are in the town my dad lives in, three hours away from where I am. I'm just so sick of it here and want to go back home.

Who was in the right? Should I have bought my sister the book? Was I being rude about it.