Hello bumblebee and welcome. I hope you find this site as supporting as I have over the last 6 weeks. I am sorry to hear about your father and the coping mechanism that your mom is using to deal with it.
I too returned home after being away for many years and I found that my mom had been drinking for the last 10 years, same as yours - vodka was the alcohol of choice and she never drank in front of anyone! Just smelt of it and was either quite bitter, over emotional, hyperactive etc etc as you describe.
I have lived with this for the last 18 months, tried to stop her, help her, save her and probably to the detriment of my own sanity and happiness. When it's your mom you have the overwhelming desire to be there for them I know this only too well.
You have the right to a career, to live your life and to be happy. If I had my time again I wouldn't have tried not to let it consume my life as much as I allowed it to in the past and ala-non has helped me to see this - so I would strongly recommend you seek out a local meeting.
You have made the first step
Keep posting here to it REALLY helps,