I want to slap your mother.
Sounds like she is just not comfortable with your decision to "go all the way" with your deafness. For one thing, she probably resents the extra communication difficulties and the hard work that comes with learning sign, and thinks you should just figure out how to communicate with her "the old way" regardless of "the deaf thing". Hearing people can be surprisingly dense sometimes, some of them just seriously don't get it, and probably won't ever get it unless they somehow go deaf themselves for a while.
The fact that cochlear implants have been in the news so much lately, along with those damned viral videos going around making them look better than they really are, doesn't help matters. All hearing people see thanks to that is that cochlear implants are a nice quick fix. They don't see that there is more to it than that. And so when someone who has gone deaf doesn't jump all over getting cochlear implants or just flat out chooses to become Deaf (as in culturally, not just physically), it is seen as a "stupid" decision by them, something that you don't HAVE to do, that you just WANT to do (which is true, BUT THERE IS NOTHING WRONG WITH THAT) and therefore you are selfish for bringing this difficulty into their lives (FALSE) and so on and such.
I know a late-deafened girl whose mother was talking to a friend of hers. This friend of the mother's was talking about how annoyed she was that her white son was adopting the hip hop culture. The late-deafened girl's hearing sister overhead this conversation, and the late-deafened girl's mom replied to her friend with "Yeah, my daughter is doing the same thing with this deafness crap. She just wants to be different because she thinks it makes her special."
You're not alone. Don't mind the attitude or feel bad about anything you decide regarding your deafness... there are no wrong decisions in this aspect. Even if you chose to never speak again and only sign, and refuse to talk to anyone that didn't sign, you wouldn't be wrong for doing so... you would be making things harder than they needed to be. But you wouldn't be WRONG.