Women man, I am so sorry to hear this. There's a couple old sayings that line up.

"Can't teach an old dog new tricks" I'm just going to assume you're 17, so she's been the boss for 17-18 years and what she's been saying has been going. Children don't have an opinion, and now that you're getting older and almost to the point of legal you are quickly approaching the age where she cannot control you anymore and that's where the "Save it for when you're 18" comes in... It's her last shred. My mom did this too.

"You can lead a horse to water but you can't make them drink" You can try and try and try to be the adult and have a calm conversation and you can do everything right on your end, but that will never dictate her reaction. You still do it though because then it will show your Grandma how you're trying to take this seriously and your mom is acting more emotionally immature than you. Grandma will see it I promise because she already has her eye out for why her daughter acted this way over a vibrator... Be prepared to apologize for your actions too. You're not fully innocent and said a few things you shouldn't have, but be better than your mom and own up to your mistakes.

Good luck and update us!

Girl, I was young. Based on your grammar I would say north of 16 at least, and that is a good age, you were handling it the correct way and I think your mom is just spun because this is probably the first time she's seeing her baby girl as a sexual being (not in a weird way- just that you're becoming a woman and an aspect of that is that you're going to get sexual)

The situation could've been handled better on both ends with some proper effective communication, but just remember 1.) this too shall pass, 2.) it's not the end of the world. My mom and I fought like cats and fucking dogs, almost getting physical a time or two (I could never lay a hand on my mom), and we couldn't STAND each other (always loved each other though), and now we're best friends. Y'all just need time to cool off.

I know pride in a teenaged girl is a finicky thing, but after a few days at your grandmothers it might help the situation if you reached out first with an apology on how you reacted, and asked if she could give you the time to listen and let you explain your side of the story, and that you love her!

Everything is going to be okay!