Maybe OP can't confide in anyone because her mum and brother are fighting cancer and there's already too much shit going on right now so she doesn't want to worry everyone?
I don't think we should be too hard on OP. It's very hard to explain how much of a number an alcoholic can do on your brain if you haven't been through it yourself.
As I'm reading this thread I just keep thinking of my poor, poor dad, who was in exactly the same position as OP (although, he was the breadwinner, so that part of the dynamic was different). And I feel like a lot of what you're saying to the OP, you could quite justifiably have said to my dad. But it breaks my heart to think of that because he only ever did what he thought was for the best. And as much as I think he got it wrong, I can't blame him for that.
We, as a family, found ourselves in this horrific situation with my mum being an alcoholic and we just muddled through it somehow as best we knew.
That's why, having been through it, I would hope that OP can have the benefit of mine and others' experience and follow the excellent advice she's had on here.
But she doesn't deserve the slating she's getting. She needs support to find the courage to leave.
I can't explain it, but when someone you love is an alcoholic, you feel so responsible. You imagine them losing their job and living in a shitty bedsit, slowly drinking themselves to death alone. And although that may be what inevitably has to happen in order for the rest of the family to 'save themselves', the thought of it is so harrowing that you try to find another way. So you minimise and compensate and compromise and enable. Because the idea of seeing them hit rock bottom is so heartbreaking. Even though that's what HAS to happen if they're ever going to get better.
Fuck, it's so hard.
OP you have my sympathy. I really hope you don't feel too got at. People's emotions are only running high because they really care.