instant flow of responsiblities make me feel panic

idk on subreddit i should post it. as i frequent here so posting it here i am 17M got a thought that i have to take everything soon over me (responsibilities) as my father is getting old. he is suffering from back pain as he has to drive over 100km a day by scooty (we don't have car) i have 2 older sister(i am the 3rd kid) the bigger one is in tier 3 private college so getting placed with decent package is hardly possible the younger one is kinda stupid or mad i have posted about she is kinda burden she does't even call mummy papa her parents she used to abuse my mother and don't have any manners she used to taunt them and i feel sad like really every member is sick of her i m 2026tard and my prep in not going well(11th ki sirf theory aati h) and after my father retire the whole thing is on my i am not running from my responsibilities it is my duty but just scared that i the only hope who is just completly piece of waste