Is AUTHOR wrong in the post ? POST : Throwaway account here

Backstory: So yesterday was Christmas, and I’m 13 and got a really nice Apple Watch. So fast forward to today, where my brother (15) had a plan to get my parents a gift. But my dad was home so only one of us could go, which he already decided was him. So he went, and took my money, which was over $20 but I didn’t care. After all, it was a gift for my parents. So then he went and grabbed it and came home (where my dad was cooking so he didn’t see him) and ran upstairs. He then wrapped it and told me he would tell me when to write a card for them, which I wanted to do. I forgot to mention I was EXTREMELY worn out because I took a straight 3 hour test (too hard to explain) and I went and played CS:GO. So he was writing cards and called me up to write my cards. I said “in 2 minutes”, and I actually meant that. But his immediate response was to shut down my computer forcefully and give me a death glare. And obviously I’m gonna get banned in CS:GO (but that doesn’t matter). His stare obviously meant I’m not writing anymore cards, and I was pretty bummed out. 

But here’s the AITA part. Since I didn’t write one my brother used my letter to write why I was selfish and only cared about myself. My parents read it and agreed and didn’t bother to hear my story. I got so many “you’re so selfish” I just want to make sure I’m not even though 3 other people think I do. So what is it, Reddit?
AITA?