What do I do when my ex calls me harsh stuff out of no where?

So me and my ex boyfriend were talking about burritos (totally random) and then all of a sudden he tells me that I don't care about him, and im just like "Yes, I do" and we get into an argument over that and he tells me to have a nice life and im just like what is going on then he calls me a stupid(female dog) and stuff like that and hes NEVER called me that before EVER in my life time and I cant just not talk to him because its too hard. I need help