Hi 16,
Depression, anxiety and substance abuse often go together - I believe it can be both a symptom and a cause of mental health problems. I started to drink because of my severe social anxiety when I was a teenager. It took me years to come out of denial about it that having to drink before facing every single social situation is no way to live a life. It's good that you recognise that you can't drink again. I'm the same.
I can never be safe if I drink - it really messes up with my head.