Hello, I (23f) cannot believe I am writing this. My brother (18m) was just caught by me and my parents doing hard drugs yesterday right after a cop came to our house to give him a warning because he got caught violating his restraining order by bringing an underage girl into the house. He started acting weird 6 months ago when he met a new friend group. My parents gifted him a car when he turned 18 and he crashed it, making it undrivable, he then started using my mom's car which he then totaled, and then finally he stole my dads brand new tesla in the middle of the night with a bunch of underage kids and his friend billy (turns out hes the supplier) and drove it into a tree totaling it. Since then he was been sneaking people into the house, mostly an underage girl (15f) who's my dads best friends daughter which he claims hes in love with. The family put a restraining order on my brother so they wouldn't contact each other but they still do and he got caught by the cops because she snuck into the house to bring my brother drugs. I discovered this because he left his snapchat open on his computer after we caught him with the hard drugs (c0ke and Blue pills). Ever since the first accident I had been begging my parents to give him consequences for his actions, but they continued to ignore my pleas until the final car was smashed.
Since then, we have been arming the house with ring cameras, sensors and alarms. As of now my dad has probably spent almost $1000 on new security alone. My parents are saying they want to section my brother (Section 35 Massachusetts) but I really hope they actually put him in rehab or inpatient. I hope they actually go through with it. My brother was a quiet, sweet, and sensitive person with not a lot of friends before this happened and now its like talking to a zombie who won't stop lying. I don't know what to do with myself, I find myself getting angrier and Angier at him and I feel guilty, he wont stop lying about everything with sometimes a shit eating grin. Last night he jumped out of an 8 foot window in the middle of the night. I can't get a night's rest without an alarm going off, and Im having extreme anxiety and paranoia. I don't know how involved I should be in this; I feel like a parent at times. I don't know how I should be reacting/treating my brother. I want to move out, but I feel bad leaving my little sister (13f) to deal with this alone, and my dad also has been saying he doesn't want me to. I really do want to leave but I don't know if it's the right thing to do.
TL;DR: my brother is abusing drugs, smashing cars, messing with underage girls and I don't know what to do