Familial relations don't follow the same rules as personal relations, as I'm sure you know.
If we were friends, and you said to me "I really don't want to talk right now, nothing against you, but I'm thinking through alot right now, is that cool?" I'd say "Absoultely, good luck! whereas your mother would say "You don't love me! You never have! I gave birth to you you ungrateful tramp!" or something like that.
I'm way extroverted but I am also sensitive to others, not everyone is, just set your boundaries and don't feel bad about it. You weren't put on this earth to take shit.