My brother is going crazy and I don't know what to do

Hi, I'm 17F, and I live with my very South Asian family. Our family is somewhat modern, yet still very backward when it comes to traditions. We're Bengalis, and we moved from Bangladesh around six years ago. We now live in Namibia due to my parents' work.

I have a brother who's now 30, and he's been a constant drug abuser since he was around 14 or 15. My mom, my brother, and I used to live alone in Bangladesh because my father was working abroad. It was kind of like my parents were separated, but they're back together now.

Our family dynamic was kind of toxic, and it still is. I wouldn't say I face trauma from it, but after moving to Namibia, my brother turned into a drunkard and a drug addict. He's constantly fighting with my parents and blames everything on them, saying they were abusive towards us. My parents are very lenient towards him because he's a guy, while it was the complete opposite for me. My brother thinks it's the other way around.

He's very violent and starts fights over random things. He's married to a Bangladeshi woman who lives in Germany, and she's telling him she's going to divorce him because he's become kind of crazy, even online. My parents don't know what else to do because they don't want him to end up with criminal charges or a record.

I'm still trying to finish my A Levels and move abroad, and I can't find part-time work here. My brother has been sent to rehab, but it didn't help it actually made things worse because he ended up mixing with other drug addicts. The environment at home is very unsafe for everyone.

I've honestly gotten used to it, and it's kind of messing with my brain. I can't stay in a positive environment for long before I end up sabotaging it. I'm sorry for going off topic.

Back to my brother I don't know what to do because he's quite big and strong. I can't even fight back because he just beats me up really badly. He does the same to my parents.

So, does anyone have any advice on what we can do? It got so bad that I even started thinking about getting married and moving abroad, lol.