Why am I angry all the time?

I don't know why, but I am angry all the time. Today I was angry at my father because he asked me to scrub the bathtubs while I'm home this week. I shouldn't be mad because yeah, I am home and not doing anything and I'd be helping him out. I was mad at my sister for asking for a ride to get a salad at mcdonald's, I have been mad (not upfront) that my best friend hasnt had money to buy me a hanukkah gift after I spent 78 bux on him for xmas. I don't know if working out helps me or hinders me. Any good solutions to make me feel at ease and calm?