How to get through a fight

my boyfriend & i got into a really huge fight yesterday. he said something offending and when he tried to apologize I constantly told him he's pathetic & he got so mad he cursed at me and told me to fuck off. he never did that before and is a nice guy. he finally picked up the phone and we talked it out. we even chilled today and at one point we talked it out. he told me he's sorry and still loves me. but i feel so sad idk why. i feel like everything's different even though it's not. how do you get past a fight