Don’t know what to think or do

My bf and I have been together for 7 years and we have a 2 yr old and a newborn. We defiantly have different personalities and opinions on things. He’s more health conscious and I’m not. We just got our own place and he’s super picky about everything not being perfect..for example water is not clean enough for him. I told him I’ll get a filter for the shower for him with a gift card that we have and he called me cheap bc it would b from target and that I can waste my money on it and he’ll buy his own for when he’s on his own. Then he pretty much said he’s here bc his kids here. I’m very hormonal bc I have a 3 week old and I just don’t know what to do. I feel like he’s constantly talking dn to me but he thinks it’s me who is to him.