AITA for having a mental breakdown in front of my sister as she was badgering me to get food for her and her kids.

Hi! This is my first post!Anyways, recently my professor whom I knew for 4+ years, and one of my close friend had recently passed away (my professor was first and then a few days later my friend passed) and I took it really hard. I'm glad my work and my other professors understood and excused me from class.Everyone in my family knew and although they never really asked if I was okay, they knew. I've had breakdowns either alone or to my close friend, never to my family because they're the type of people who think breakdowns are just me being dramatic. Anyways a couple of days ago when I thought I was getting better (I hadn't cried in like 3-4 days) it all came tumbling down again and I had one of the biggest breakdowns I've had in the month. I went to my room, then I came out(still kinda teary eyed, enough to wear my sister would notice if something was wrong) and my sister had come over with her kids. When she came over, my dad wasn't home and she needed to do laundry at our house. I didn't really care nor did I have the thought process to care so I just went up to my room and go to sleep. 20+ minutes later she storms in without knocking, and demands that I go get food for her kids. I say no and try to shut the door and she places her foot before I can close it. She keeps trying to bring up the time where she got me food once and how I didn't repay her (which I did, I bought her food that time as well) I ask her why she couldn't get food and her excuse was " I don't want to put my kids in the car again " (they're still in car seats) I told her that's not my problem and try to push through her to get to the bathroom to where she grabs my arm and calls me a "spoiled brat". I yanked my arm and said "are you fucking serious, why are you fucking here doing your laundry?" and at this point I'm breaking down in tears and she says "why are you crying, is it because you didn't get what you want again" I said " NO IT'S BECAUSE MY FUCKING FRIEND AND PROFESSOR DIED AND YOU NEVER CARED TO CHECK UP ON ME YOU SELFISH" before I finished she slapped me saying I should've never talked to her like that. She called me an asshole and then left with her kids.I've been debating on whether or not to apologize to her because she called my dad crying saying that I yelled at her and my parents are not willing to hear my side. So AITA? via /r/AmItheAsshole https://ift.tt/362dVPV