Is my mom trying to control us?Watch
It sounds like her ultimatum is "if you move out of my house, I'll sell it and never give either of you any financial support again".
Assume that if you do leave, there will be no chance of any inheritance and little positive communication with your mother.
The only question is this a price for freedom and privacy that both of you are willing to pay?
For me the consequences of escaping were vastly preferable to the consequences of staying and I will never go back.