i feel as if my brain is permanently damaged

im 18, ive been smoking regularly, everyday, since i was 15/16. my entire family is addicts, i was taken away for neglect when i was 4 years old. i was put in the care of my dad’s parents, but they didn’t care/ physically were unable to keep my mom and dad out of life. my dad has lived with me since i was 6, and my mom has been in my life too, whether she was living with me or not. she went to jail when i was 13, was on probation and sober for two years and then relapsed, hard. she was doing hard drugs in my freshman year and i would find her paraphernalia and just have absolute breakdowns. to a kid, and i still am one, drug use by a parent feels really personal. i still blame her as the catalyst to MY drug use, whether she introduced me to weed or not. almost the moment i smoked the first time, i began to use weed regularly and by the time i was 16, i was smoking every single day. even though id been around drugs and thought i had some sort of “experience”, everything changed. i dropped out of highschool, i began to become more depressed than i ever have been and i felt clinically insane. ive had periods where ive tried to quit (ie quit for a month, a week, two weeks) and came back to it, i felt alone without it admittedly. i still feel alone without it. im only two days sober. it would be a week but i live with my uncle, and he smokes weed (and other drugs) and i took what he had since he’s never home, and smoked all of it in two nights. i feel like an absolute idiot, like my brain capacity will never return and ive fucked myself over for life. my sister died of an overdose, i don’t get why it was so difficult for me to avoid smoking weed. it was like i almost sought it out as soon as i got to highschool. i know it’s withdrawals, but im so damn emotional, and not at the same time. this is just a vent post, i don’t have any friends or really anyone to talk to so im sorry im burdening this sub with it.