How can I help her with alcohol consumption (and drugs in general)?

This question is bothering me right now… because I'm worried and scared for my girlfriend.

Over time, I've noticed that she's no longer able to control her alcohol consumption. At the very least, she's developing a drinking habit that won't end well if she doesn't change it soon.

She drinks excessively every time, and she does so deliberately. She drinks with others as often as possible and can't refuse. She also drinks during the week.

She says she has been doing it since she was 13 (a few years now) and that no one ever took care of it and that it was rather offered to her, even at that age (13), by her parents.

I also generally have the feeling that she drinks to run away from insecurities and fears…which she doesn't really want to share and doesn't dare to, but rather tries to drink them away.

Or alternatively, she smokes weed… Generally, none of this bothers me and I do it too, but she does everything excessively and deliberately ignores her own limits….

And I keep asking myself, how can I help her when she shows outwardly that she doesn't want to accept it and downplays it and tries to avoid the conversation?

(This question is aimed primarily at younger people, or at people who drank too much at a young age, or were at similar points in their lives)

The text is very confusing, but I hope you can understand my concern and, above all, that one of you might have some advice.