Hi, this is a hard one to answer.
It made me think about our experience with our sister. Same. Whe she broke up with her ex she too drank more and more and her behaviour became outrageous (too long a story). It could be that your mum is just so embarrassed by it all and the drink is controlling her and her behaviours. Shes obviously going through a pretty rough time of it. We tried just letting our sister know that we were there for any support she needed to stop her drinking, and helped her get to appointments.
Doesnt sound like your mum is ready for that right now and may still need to do some more. I really feel for you at this stage, it can be very frustrating indeed, so you may need to take time out for yourself and family and let mum alone for a while. She may need to see that you wont put up with her drinking and behaviour. I would suggest however that if you can get her to see a doctor or AA type people with infor, it is a start in the right direction.
Thinking of you, JJ