In theory, parents are supportive and helpful and so on.
If thats the case, great.
Unfortunately in practice, many parents are not supportive, not helpful, have their own problems they haven't yet resolved or have no interest in resolving... ie they're humans and have flaws too.
If your parents are flawed and aren't supportive - you are not going to turn them into the parents you want.
That is the bottom line. So either you sort yourself out, move out, live your life for you... or you waste your time attempting to turn these people into who you want them to be.
Take it from someone who has already tried that, it doesn't work, it will never work and they'll take you down with them.
FWIW it sounds like you do understand the difference between healthy and unhealthy drinking habits and you're probably ready to move away from them, or at least put into motion the things you need to, to achieve that in the near future.