Hi and welcome Jay
I don;t know anything about social drinking - tried to do that for 20 years and failed dismally.
Once I got the taste of alcohol nothing short of oblivion would satisfy me.
I do wish you the best tho - and with your domestic arrangements too. Your current living arrangements don't seem great - I hope you can find away to move out and not feel too guilty.
Maybe some of the other people who make up the 'us' in your house could step up to the plate? or maybe there'd be some help for your mum if you did move out? Might be worth investigating.
I hope you can convince your mum to see her Dr too -if her anti antidepressants aren't working she needs to sort that out. If she's drinking too, they probably wont work at all, no matter what kind of med they are
Like I said I wish you the best. If you find cutting back is hard to do or impossible to maintain, we're here to help
D