He brings that up every time...

Ive been with my so for a few years now I have a kid from previous relationship one with him currently pregnant with second when we started talking he knew I had my son I never pushed him into taking him in as his own my mom on the other had always told me he had to it was the 2 in 1 thing .... So today we got into an argument because I told him he needed to help with the kids a little he does nothing around the house to help me out I do it all he was unemployed for 2 months just started working a few days ago I told him I wanted to get a temporary job possibly at night so we wouldn't send the kids to daycare he told me I needed to find someone to watch my first son over night because he can't handle em both they take forever to sleep I told him I watch them 24/7 and he should learn to watch em both he went on to tell me that my first son is not his responsibility and that he didn't have to watch him ....I am hurt he brings it up every time i know he feels some type of way about my son he doesn't treat him bad but he had definitely made sure he knows he is not the dad ... My sons dad is not involved at all because he never wanted to be involved today he had the nerve to tell me that I'm pretty much a hoe because my sons dad didn't want him he was a mistake I'm just so upset this pregnancy hormones are not helping eather I just don't even know what to think anymore ....and it all began when I asked him to help me out with the kids just a little bit more I know he gets frustrated at night when he is trying to relax but he doesn't understand that I don't get to relax until they are sleeping and on days they are sick I get no relaxing it's a 24/7 job 😩 am I a horrible person for needing help ...