breaking up

Micaela
I've been dating this guy for 5 months almost 6 months now and things were really good amazing even. Then a few weeks ago he has become a total douche ignores me only needs me when he wants to have sex it's frustrating.I get days where I can't get up Bc I have so much anxiety in my stomach from the relationship. I'm ready to start anew. How should I break it to him?