I waited for my sister to eat ice cream first to see if it was poisoned
What would make you let her eat it first?
I just wanted to know if it was safe to eat, so I decided to see how she reacted to it.
If you had a legitimate reason to think the ice cream was poisoned, it was unkind of you to let your sister eat it. She cold have gotten sick or died. But if you were just being paranoid, then you should consider seeing a mental health professional to help you work through your delusions.
I don't have mental problems. Just her stupid face is making me feel angry.
I suggest you do seek a professional to help you. You are displaying irrational anger towards your sister for no reason.