I'm sorry to hear that there are challenges in the relationship with your mother.
It sounds to me by reading through what you've written there's a lot of other background issues that you're facing too (you've touched on the money and money spending pattern in your family).
I'm sorry to read your father passed away
You sound very sensible to me with the way that you go about budgeting.
Kuddos to you for telling your mother that you need space. I think this is a positive step forward in you finding your emotional independence and it's your time now, after all you've been through throughout these years, to have your own mental health put first above and beyond anything else.
Please feel free to continue to post and let us know how you go.
You matter to us.