Why am I so angry/ frustrated all the time?

PLEASE read :( i need help. I am a 16 year old girl w 2 happy parents and an older and younger sibling. Before my brother went to college, he was always the angry one. He'd yell and curse and be so nasty sometimes. After my brother was gone for a few months, I became the controlling one. I hate my parents (especially mom) with a passion. i dont give a **** if shes my mother. i still hate her so much. the slightest thing can get me so mad. for example, today my dad is bringing home my least favorite kind of bagel because i was in the shower when my dad called asking what i wanted. my mom didnt care that i had a HUGE workout this morning and was starving. she just said "i cant ask her what she wants my hands are full"... later i found out she was just mushing ricotta cheese... what she couldnt walk 30 feet and yell into the bathroom? yet she was able to pick up the phone.. i recently lost 10 pounds and he baught me a toasted everything bagel full of butter. ew. so i said im going out to buy a bagel and she said no you are to just sit down and help me clean. i had a shittt fit. i get so frustrated and so angry over the simplest things. what's wrong with me? i always feel so upset, frustrated, and out of control. the slightest thing will trigger me. i cry constantly over nothing. am i just a sad/ angry person? i dont mean to sound spoiled but everything always feels out of place and im going crazy. i already tried talking with them about how they feel. instead they just rolled their eyes and said "i think youre being really emotional." and walked away. HELP. D: