My ex (25 yo female) asked me that stupid question about a week ago, I said marriage is not going to change anything, we wont have mutual investment fund or smth (I make $20k more than her), I don't want a baby and I feel too young for marriage.

She literally implied that she wants to marry just because her best friend is recently engaded. She had been liking wedding pics, wedding cakes and rings all day on instagram for the last few weeks after this.

So anyway, I dumped her and she went crazy. She is making up stories to her friends about me, claiming I was beating her (never hit her), accusing me for cheating, sending "sexy texts" to my friends.

She wasn't crazy before, she is a computer science major, has hobbies like paragliding, reads a lot but now she is acting 100% different. How to remove her from my life?