feeling hurt and upset

My and my partner had a massive argument last nite he said a lot of hurtful things. We've talked a lot and managed to sort it out but the hurtful stuff just keeps going rd in my head. 
Why do men have to do it for throw stuff up out of your past and use it against you. It's the first time he's done it but she said he's sorry etc.
How do I get past this I love him so much