My kids dad don’t have any patience with them

I feel so bad for my kids . Me and their dad is still together and lately we have been having so many arguments about our parenting . When I was younger I have gotten whoopings. Some id say was needed but most was not. I was on punishment for accidentally forgetting to do my chore one day . I was on punishment for getting a bad grade on a test or progress report (I’ve always brung the grade up for report cards never had a D on my report card) I was called fast before I was even having sex . I would get yelled at so bad if I didn’t know a problem on my homework’s . It was so bad to the point that as I got older I stopped bringing homework home and just did it at school. In my moms phone my contact name is just my name . My brothers name is “mommy’s baby” . So now I’m grown up and don’t have a mother/daughter relationship. I have a daughter and I promised I wasn’t going to be like my mom . I was going to have more patience. So when my kids do something I don’t want them to do I’ll tell them stop , I’ll give them atleast 2-3 chances before I start getting frustrated and yelling or tap them on the leg/butt/or hands. My boyfriend (their dad) feels like that’s why they are crybabies because I baby them. He plucks them in the forehead over something very small . He yells in their face . Like today he wanted to record himself reciting music lyrics and my son screamed (he’s 2 and doesn’t really talk so I’m guessing that’s his way of communicating) my boyfriend instantly snapped and yelled at him . He tried to make the video again and my daughter called my name, again he snapped and told her to shut up . He called them dumb in front of their face . And said my daughter is below average . He said he talked to other people and their kids are younger than my daughter (she’s 4) and they know how to write already and knows more stuff than my daughter . I told him she knows everything she’s supposed to at this age , she’s not falling behind at all. And don’t ever compare kids. Kids have their own pace at things . I told him that’s like saying my brother had adhd when he was younger but grew out of it so he should have grown out of it by now. They’re their own people. Now my bf wanted to get out the house so he decided him in the kids will chill in the car until I get off work . My daughter is making these noises and he screams and tell her stfu . I said well you have them sitting in the car for 4 hours , you should atleast be more patience and let her do whatever to keep her occupied even if it is making funny/weird noises . My kids are so respectful , the have manners , my daughter is the sweetest ever , they are cry babies but oh well . I feel so bad I chose someone who just doesn’t have any patience and talks down on their own kids . They’re only 2 & 4 . He says just because my mom did what she did to me growing up doesn’t mean not to discipline my kids . I do discipline them when necessary. Then when I don’t discipline them to his liking he’ll say stuff like “oh kids yall can do what y’all want , I’m done disciplining yall” and he feels as though I’m trying to make him out to be the mean parent that does the discipline while I’m the nice parent