I feel like I'm going to grow up to be like my alcoholic mother
Why do you think you would grow up to be just like her?
Because I started drinking alcohol and I don't know what to do with my life.
I'm sorry you are feeling that way but it is undesirable to be an alcoholic. You can make better choices now so in the future you don't end up like your mother. I would seek out someone to talk to, someone that can help put you on a better path.
It's not going to work out because it never did for her.
You should have more confidence, many things have changed since your mother was an alcoholic. There are better services out there if you would just try, staying a big drinker is not going to be fun. I expect that you will respond positively to it all, you'll see.