tips on disciplining a 3-year-old throwing tantrums

So this is actually about my (20f) brother (3m). He hasn't been eating well these past few days, he barely touched his dinner so we said he wouldn't get any sweets. He's now yelling at the top of his lungs that he wants a popsicle. We try to explain he gets no popsicle till he finishes his chicken, which makes him scream even more. My dad kept trying to tell him no because he didn't eat dinner and my mom told him to just leave him alone and ignore him. I'm not entirely sure that's helpful either.I take care of my brother most of the time since my mom has covid and is quarantined in the spare bedroom most of the time, I just don't know how to deal with him. I never yell or hit my brother, I never show him any kind of aggression. I believe that's wrong and no child should ever experience it. Most of the time I can actually talk him down or reason with him surprisingly, but when it gets *this* bad where he's screaming and such, I'm at a loss. Nothing seems to work.He's also awfully moody and will react with annoyance/anger at the most random things. Even when I'm trying to be sweet or funny or just playing with him, he'll get so mad at random things I say and sometimes even hit me. It absolutely makes no sense. via /r/Parenting https://ift.tt/3f0vLDu