He had a baby on me 😕

My boyfriend that I've been with 1.5 year cheated early on in our relationship with his ex and she had his baby a few months ago. I didn't find out till a month before the baby was born n I am hear broken. i am trying to get past it but I am broken. when ever I get angry I belittle him and talk to him very badly and its creating a wedge between us. I love him but idk what to do....