was i wrong in this? getting hit

my SO and i were on our way home from the nicu, which is an hr drive away. he was talking about how he doesnt trust them to take care of our baby. that they could be treating him w bad care and when we came, they pretend to give him good care. i responded that he could be right, i wish i can bring baby home. wish he didnt have to stay so long. he repeatedly said hes so smart for thinking that way and that we shouldnt trust those ppl too much. then he ask me repeatedly, if ik what hes saying, do i think hes right. i f'ing had to repeat myself that i do because he kept asking the same question. he then hit me and he hit my engorged breast, i got upset, and raised my voice that i do understand! he got angry and ask me if i want to start problems. telling me to quit arguimg back w him or else things will get worst. i told him he hit my engorged breast, he said he doesnt care, and that i wasnt taking this serious. he said i deserve this. he said i take this as a joke and think hes playing around w me. he said he doesnt have time to deal w my shit when he already have to deal w worrying about our baby. if i dont shut up, hed do worst. he said he doesnt care if he hits my painful breast, i get what i deserve.