I'm about to tell my intrusive mom off
Why do you feel like telling her off?
She was being so annoying towards me
You shouldn't tell someone off even if they are being intrusive. Ask them calmly to give you space.
What? Why can't I tell her off.
That will just make her angry, and she might stick around to argue. If you really want her to stop annoying you, be polite so that she'll leave.