Just got dumped

We had a huge argument about him going to his step brothers girl friends house alone. It was just them too. I wouldn't have had a problem but he lied to my face about it when I knew the truth. Then today the girl comes over to his house and I of course freak out. He's done this before but the fight got so bad he was cussing me calling me every name I'm the book and dumped me. Now I'm just ignoring him balling my eyes out wondering if I'm in the wrong. Please help