He got so angry

My boyfriend and I have been together since last August. And I love him so much I'm pregnant with twins that we planned. But tonight I want down to check on him we were waiting on his nephew to be dropped off I wasn't surprised to find him asleep at the table. But I found a text message he sent to his ex gf thanking her for some pictures she had of him back from high school. I wasn't upset that he got the pictures just that he didn't tell me. Well he got so angry over it all because I was upset he hid it from me, he broke his phone and put three holes in the wall. He's never done this before ever and broke down in years afterwards about it all. But it was so scary.... I'm lying awake while he's crashed out next to me and I just can't get past what just happened. He's so sorry and I know it but I never expected any off this from him. My feelings are so hurt and I just can't believe the way his temper rose so quickly and crazily.