Iv been in the same situation but different circumstances. I know its hard but ur mum has to realise she can’t rely on alcohol my mums been a alcoholic since i was a baby and although we don’t live together we still keep in contact, and now after being her carer for years shes pulling herself together slowly. Best thing for u is to just tell her ul be there for her and in time she will come round. In the meantime although its hard just concentrate on ur life. Shes maybe isolating herself in a way to protect u from seeing her upset and drinking, one day she will have a wake up call and it will be horrible for her. Its good uv expressed ur feelings best thing is to be honest to a alcoholic. i hope this is some help to u feel free to email me if u ever want to talk i can totally empathise what ur feeling and going through
my email is rachael.fletcher93@gmail.com x