I think Mum has a problem, someone help please

Ok, so I don't really know how to write this... but here it goes.

My mum currently drinks about two bottles of wine a night in the pub, she always comes home drunk. It started when she split up with my step dad, she drank about 2-3 glasses a night & from there it's got worse to her current 6 glasses a night. The break up wasn't nasty or violent or anything that could have turned her to drinking & it's only got worse since she got with her current partner.

She smokes about 20 cigarettes a day too.

I moved quite far away with her & her partner in her fantasy of a new life, new family.etc but now I spend my nights at home alone whilst they're in the pub. They quite often drink at home too.

I'm so worried about my Mum & have tried to tell her about my concerns but she gets defensive, aggressive & often tells me to "get off her back".

It's literally killing me to sit here & watch my mum kill herself with alcohol & cigarettes. I desperately want to get her to stop or even cut down but I don't know how.

Please someone help me.