YANBU.
My parents have a VERY similar situation with my sibling so from experience I know YANBU.
I have no idea why SOME individuals believe they should live for free and get everything handed to them. SMH.
I understand your frustration OP and you are 100% NBU at all. Where does he get off, thinking he can live for free? Even if you have pandered to him while he was under 18 he is now an adult and needs to behave like one :( I am so sorry that you are having this experience. unfortunately my sibling is 30 and this is still going on for my parents.
Full disclosure my sibling is also a drink and drug addict. However they are what is called a fully functioning addict as they can hold down a job and see their child.
so I am not sure this will help but here’s our Family storey. I have a 30 year old sibling who still lives at home. They have a young child (the child is 10, and they are no longer with the other parent). They work 40+ hours per week and, sometimes 2 jobs as they have a trade so do private work on the side. Easily takes home 2500 a WEEK. However, they never pay rent, always expects my parents to buy toiletries and clothes for them, give them petrol money to get to and from work (as their wages are spent by Saturday morning after been paid on a Friday), they never pay their mobile phone bill (it’s in my parents name) and, frequently moves new partners in so my parents have to feed them as well as my sibling.
They constantly say that they will pay and don’t. The only time they have paid their own way was when they moved out for 6 months, but they got themselves in so much debt by not paying water rates, and electricity etc.
The ultimatums my parents have given them have fallen on deaf ears. They have tried to throw them out, but they just return and sit in the garden until they are let in the house or create such a scene that my parents give in. My dad half the time won’t even speak to them as he gets so so so annoyed at how selfish they are.
I am 1/3 and myself and my other sibling are nothing like this I got a PT job at 16 and paid 1/4 of my wage to my parents and my youngest sibling did the same but the middle one is just a waste of space and a free loader. :(
I am not sure the above will help you but PLEASE do not get into the situation my parents are in where their seems to be no light at the end of the tunnel. Please do what you can live with as soon as you can x