My family is making me feel crazy and emotional?

since m step dad and step sister moved in with my family, it changed how we were. my family is very open, happy, and family dedicated. i get along with my mom and two brothers. no social problems and secrets at all, but this was around since i was like 8 years old. i knewmy step dad since i was born. he was my moms coworker andhelped my mom since she came here from phillippines in the mid 90s. my step dad liked me more when i was younger then now. i was excited to have a step sister becasue i grew up with brothers. she is 5yolder. she didnt talk much and the only words that came out her mouth was how much money she needed and what she wanted.her sneaky and quiet self attitude rubbed off on me year by year. i hate my sister with passion because her attitude and habits irritated me so much and i hate how her fat white aass comes out her room because im usually happy when shes preoccuppied with her laptop hiding in her room. i know its bad to think this way but its so complicated in this house. i keep my anger and thoughts in my head for years and its like eating me away and changing me and like i only act like this at the house or when we do family trips. i wish my step sister moves out because since they camehear we started departing from each other and we talk behind each others backs and other horrible problems that makes me want to explode or punch a big hole. i dont know but its kind of true that everyone is happier when shes gone for a while. my thoughts give me anegative vibe when ever i think hard about her and it pisses my mom when ever i seem unpleasent. this sister is my only excuse why im never the same. before they came here i was realy talkative but now since our family is so awkward and cold and detached i dont know how to talk to my family anymore. and i am the youngest and it makes me feel the deepest in the hole and this family is making me feel so unhealthy but im 15 and i blame the whole horomones-teenage-pubrty phase andmy worst mistake was being introduced to drugs at school like marijuana and ecstacy and shrooms! like for 7 years ive been fighting myself and it makes me feel like im developing a mental disorder and i cant manage to ask the damn doctor because im too fcking quiet. i always feel anxiousand worried and like i feel like im in deep shiit and sorta paranoid andi feel hyper for acouple of minutes. i mentoned this to my mom but shes jus thinks im getting oblivious and exaggerating about it and then i would fight with myself in my head and think how retarded i am. im glad im finally saying this and srry for the misspellings because im doin all this on a kindle