I need advice...my husband has been extremely verbally absuive our entire relationship. He didn’t actually start calling me names until after we got married (why did I marry him right?)

I’ve been contemplating divorce for a month now, my daughter is only 11 weeks and 4 days old. She loves her daddy, and he says he loves me. However today I was gone for 20 min, I get home and I hear my daughter screaming, not just crying screaming so I run inside. My husband is towering over our baby while she’s screaming and changing her diaper telling her to “shut up” he effing flicked her on the mouth before I got home, because she wouldn’t stop crying...he wouldn’t tell me why she was crying in the first place. When I told him to give her to me and how dare he flick our infant, he told me to shut the f up and made like he was going to kick me...I have a contingency plan, but how do I pack without him noticing? How can I prove what he says and does? Flicking my infant pushed me past my limit...I just need advice...do I stay if he agrees to go to anger management? Do I leave? My baby loves her daddy...but no fatherly figure is better than an abusive one right?