aaand that is where you make an excuse, walk away and just let her deal with it on her own. Then, if you live at home you quietly get on with your shit until you can move out and if you already live on your own you go home and just don't call her for a while.
Parents who say shit like that can end up de-motivating a kid to the point that they make them fail.
Sounds like your mom is frustrated because she doesn't know how to do all this herself. Sorry, at least you know how to DO the internet on her phone. I think you should have let her struggle with it a while.