Thinking about him gives me butterflies in my stomach

I don't know why or how but thinking about him makes me anxious, I lose my hunger, and anything I do with good taste I get lost in what I'm doing and I feel butterflies in my stomach, that didn't happen, because I already knew him and yes I had/have a relationship with him.

This all happened after an argument between us, in which he acted completely differently towards me, he put the blame on me, but he doesn't know how much I was hurt by knowing that he liked photos of other girls (photos with other purposes that you know what it is) 

Well after all that, knowing that I was right and because I asked him to apologize he apologized to me, and he's acting normally like he loved me, I asked him for a break, he understood, but he won't stop sending me messages, that's why I'm dying of anxiety because I like him so much, but I don't even want to see his face anymore. IDK WHAT I DOOOO I hope this feeling ends soon, I wanted not to develop feelings for anyone, I didn't want to feel pain