Family at crisis point with cancer and alcohol

Hi all. I barely know where to start and this is long and so complicated but our family is at crisis point for cancer and alcoholism. My father has been ill for 20 years mostly through alcoholism (liver disease and liver cancer the last 5 years) but add in haemochromatosis and asbestos lung plaques it’s amazing he’s done this well. He has been at death’s door so long we are probably to outsider strangely unemotional he’s been told he may only have weeks left. 

The crisis centres round my mum. She is an alcoholic too but has always refused to accept it unlike dad who quit 9 years ago cold turkey (its only 2 bottles every night, how else could I have coped with your daddy all these years, you don’t know how awful it is etc). He’s so hurt that she didn’t support him at the time and just carried on drinking. However being an Irish family we don’t talk about stuff and it festers. He has never told her how he’s felt. Mum is always right and can never be called out and your worries just get brushed off. She is the arch domineering matriarch but refuses to see how she controls every situation. She thinks she’s being strong and in charge. Having come back home to NI from England I’ve found the most toxic atmosphere: mum still going down the pub every night on her own to have a laugh with all her male friends while dad cooks dinner and both every sitting every evening in a completely separate living room to each other. They have danced this weird dance for years loving each other but barely interact. Neither talking to each other and basically pretending nothing has changed even though dad is so close to death he is a withered skeleton. I sat and chatted to him about how he is and faced the elephant in the room and he wanted to talk. He said how mum just seems to prefer the pub to him and when asked if he wants ti be doing all the stuff like cooking and heavy gardening he said ‘yeah sure I really want to be washing dishes but hey no one else is offering’. And so we go on this merry go round of pretense; dad about to die feeling lonely and unloved with no one to talk to apart from me it seems and mum so desperate to convince herself that dad just wants ti be normal and carry on the same routine driven life because she doesn’t want to go through all the abnormality and pain of having to actually talk to him about this. It doesn’t help that have never had interests and completely antisocial apart from mum going to pub to escape from home (I’m not unsympathetic to the need for an outlet but she goes there every day like clockwork 4.30-6 and then back home to drink more on her own).

Anyway long story short in my 4 days here I have tried gently to call her out on this (we tried an intervention at Xmas and got told to load off/I’m fine/my life so difficult) and that she’s only got a little time to reconnect with dad but she’s too scared to do it. She cried for first ever time in all this and said I don’t know how to do it, what does he want from me? It all reached a head last night when she abandoned me and dad when a relative came to visit dad. It looked mega weird her skipping out. She got arsey that I called her out on this and how the visitor wasn’t for her and I couldn’t hold back. I spilled all the things held back. How my sister and I can’t deal with the fact that we are losing our dad to drink and she continues ti drink herself into an early grave and how could she voluntarily choose to put us through this again. I just got told nastily to leave her alone and not the time etc. We have had enough of how drink has blighted our family all our lives and our pain is completely dismissed. My sister has said when dad’s gone and dust settles she’s giving her an ultimatum of booze or us. I just want to cry all the time with how damaged my family is. Where do we go from here? I’ve let the genie out of the bottle by sharing all my anger and pain last night to no avail.