Children of Addicted Parents and People

I'm 18 and don't know if i'll class as a child but need to talk to someone! My dad died when i was 10, so abot 8 years ago and my mums mum ( my nan) in the same year, my mother has always loved the drink and i used to find her passed out in her bathroom all the time many years ago. For the past few years shes enjoyed going out and been drinking a lot but shes been fine and been able to carry on with work and managed to control her drink , even if she does get through a 2Litre bottle of wine a night. However in feb this year she had a minor opperation that she would have recovered from by now but she is living an unhealthy lifestyle by not exercising, not eating and drink excessive amounts of wine everynight. My brother and i recently found out that she had a lesbian affair with a cheating, lying woman which is sent my mum into a downwards spiral. She gets uncontrollably drunk most nights and sleeps throughout the day, she hasnt been to work in months clamining shes still 'recovering' however she is slowly killing herself, she went from a siize 14 all the way down to an 8 and she looks visabily unhealthy. Its christmas today and she slept for the whole day, which resulted in me and my brother serving the christmas lunch and eventually waking her up from her drunk coma and she just sat at the table not eating anytthing. Itrs been so hard for me to deal with seeing as my brother is at university and is able to escape it but itsr too much to handle. In her sleep she makes noises as if shes in pain and it hurts to see her like this because i couldnt bear it if she died as id be all on my own. Shes still in love with this woman and itrs sending her downhill. Everyone is worried but she wont listen to anyone, and its me who has to watch her while she passes out, falls over anything in the house and throws up over herself. Shes lovely when shes sober so i'm torn between loving and hating her. Can any one give any advice or relate to this? XXX