I'm 16 and I feel like a housewife

A
As the youngest child in my household I am the only one who cooks or cleans. I'm no longer allowed to hang with my friends if my mom is gone because my step dad and 20 year old brother apparently cannot cook for themselves. I clean the house daily, clean my parents and my brothers rooms when needed, do all the grocery shopping and do everyone's laundry. I'm not allowed to get a job because no one can do stuff for themselves around here. On top of all that I have to get amazing grades or I'll get grounded and am also expected to participate in after school activities. Idk what to do anymore. I leave for college soon but idk if I'll be able to afford it if I'm not allowed to go make money. (I'm so sorry I just really needed to vent)