I don't mind confrontation at all but when I am tired of people I do step back and they respect it. Unless they are going to come and stand outside my front door (which they're not) then they have to leave me be.
The one thing I've learned is to keep the negative or toxic people away from me. If my friends are having bad days they usually tell me, thank goodness.
You can't change moms so it is best to step back for a while. You don't need to explain to her but if you want to just tell her "you need your space for a while" and be prepared for her to hold that against you as any nutty mom would do. lol
Take time for you. You are worth it.
Good luck