<human>: Hey guys, so who's in the wrong here?

Background: I've never really liked birthdays or cake. Cake is just a personal preference thing, never liked the texture. Birthdays, I just felt a little uncomfortable with. Haven't had a birthday or presents since I was like 8. 

I've been losing weight recently, on /r/keto and intermittent fasting. Sounds scary, but it's perfectly healthy, not an eating disorder or anything. 

My 18th birthday was today and my mom, knowing all of this, got me a cake. After finishing dinner, I said I didn't really want any and went upstairs to finish my homework. She got really mad and started shouting at me.

I'm totally happy to do the birthday/celebration stuff for her birthday or Mother's Day to show my gratitude and appreciation, but today is my birthday, why do I have to do something I don't want to?

Summarize the given text in a few sentences.
<bot>: 18th birthday, didn't want to eat cake because I'm on intermittent fasting and keto (and never liked birthdays anyway), mom got mad.