Was i wrong to take him back?

my boyfriend was drunk on saturday the 13th. my son's party we played games and etc than when i was getting ready to go home to get my son's play pen he left he didn't get back at my mom's till 3 am he was gone for two to three hours than he showed up we got in a fight over nachos cause i didn't put any up for him he tries to leave so i went down the street to talk and he started yelling at me than my mom comes out and he starts calling her names and etc than i let him leave went back in house he showed up later went to lay down son woke up from nap and tried telling me to change him i already did than he took off again found him later told me we were done and that he hated me never knew why i dated you told me he didn't want to be a father anymore he wanted to be a drunk well later that night which was my son's first b day he came back still drunk told me he wanted help so i took him back now my brother wants to kill him and my grandma hates him was i wrong if i was than why if i wasn't wrong why