This is going to be hard to take in
but you do not always know the one on one
personal history and dependency two people have.
The person you see today 50 with bad health in a bad place.
That person may have helped your mom through an even worse situation than you're going through - whatever they have between them - I think you've got to respect that - those two have something - walk past him - respect the fact that he's your mothers friend - say hi
Like Riv says - work on moving out
And at the same time - in your mind treat it as a grace period - you've had the physical altercation - you've had the strong words - you've had the death stares - the toxic body language - Draw a line and say ok - done that - now I'm going to be me.
Theres enough sadness in that house. This may seem impossible but while you are there try to laugh
One place I was at - it was terrible - To protect his spirit one guy would sing and he was an awful singer - but it lifted the atmosphere - I used to talk - I talked to the people I hated - I wasn't going to be like them - I was going to be me - Fair to everyone - If you keep in your mind at all times everyone - even a completely insane psycho - can do something that can actually help people - it can make it easier to talk to and to be polite - over time if you do this enough - you will develop very good people skills - in my case - some enemies became warm allies - People are funny.
You have a fight and a flight instinct
Turn off your fight instinct (It won't help you or your mom)
Go with the flight instinct
Although you don't have an option out right now - Today - right at this second
Say to yourself I have a new job I'll be starting soon - You're obviously intelligent
And put all the energy and all the thinking and 'feels' you would have put into getting your point accross, winning the battle of the living room, winning your mom all that energy all that thought all the research into this situation - all of that energy into actually getting work - opening up your wings and flying the nest.
Everyone has to fly the nest at some time
All our stories are different
As you get to work on your own story
to make it easier on your mom - to give her some solid memories of you when you're gone - show her you - her son - at your best.