Are there social services of some kind given his addiction?

I helped provide for my family when my Dad broke his back
I was 17 and in the military ,
they gave me a hardship transfer to a Coast Guard station that was only 10 miles from my parents home
After Dad had surgery and was recovering ,,they sent me back to my first duty station
you could look into the Service or the Reserves
its a steady income and a 6 yr contract
and they might even give you a TAD assignment close to home after basic so you could be there to help with your brother
the loss of income may also qualify you for more assistance ,
like nursing care and meals on wheels and stuff like that for your brother
but your Mom married Dad for better or worse
He needs to go to rehab and you and Mom need to find jobs
I know people who ride scooters ,,pretty cheap ,easy to finance and cheap on gas ,,,I am a Vet
To get my kids back and to get into a home to show stability,,
I washed 30 cars a day ,in the cold with a bad back and bad shoulder until I finally got my disability I had been fighting for
To go from running boats in service ,,Working on Locomotives ,building and running all types of heavy equipment ,building homes ,
to washing cars was pretty humbling ,
but i needed a job quick and the detail job was right then so I took it
5.00 an hour to start with
I ended up managing the company ,
so when we are faithful with little we are given much more ,
if you believe in God ,pray ,and trust Him to open doors
He always has for me ,,even when I hated His guts
He knew I believed in Him ,I hated Him

You have a lot more options than you think. Personally I would not suggest you help those that are unwilling to help themselves. Instead if you have to help someone help the one that can't help themselves, like your brother. Move out, get work, join the military, or whatever you want but get away from your parents. But keep on eye on your brother. Refer him to social services if you have to in order to make sure his needs are met. If your parents aren't willing to step up and take care of him then when you get settled have him move in with you. That will be really hard on you so don't do it until you are settled. If his life is in danger at home and you aren't ready to bring him to you, then don't be afraid to report on your parents. They have made their choices, and it sounds like you have talked to them about changing things. If they refuse to get the help they need, then don't waste energy trying to help them. There are programs out there for your brother. But you wont be any good to him if you can't take care of yourself. Good Luck.

Why is your mother not willing to work? Sounds like your step dad needs to go to rehab.

How about you apply for benefits?

marry a man with money and live happily ever after, princess. The end.

Search for any NGO's to help with your brother's condition, tell your mom to work for the sake of you both (the children) and you can somehow find a job...hope you find the way

So sorry addiction wrecks so much. I know. The addage let go with love.... you need to help yourself and your brother not him at all. Draw a strict boundary on what you'll pay towards food, bills etc and stick to it

It's not your responsibility to support your parents. Nobody wants to work but your mum might have to step up and get a job.
Your step dad needs to sort himself out!
And your mum needs to look after her kids.
Good luck.

I will pray for you to get the strength you need to overcome your difficulties.

Prayers for you with that.

Your stepdad should be going to reha, that's for one