just don't know what to do

Hi I am new here and just hope I am posting this thread in the right place. I really need help and advice with my relationship as I feel its going to end badly at this stage. So I have three children with my ex that I love more than life they are funny and amazing. Anyway we have all moved in with my now partner. Who I love very much but I just am starting to really feel like I made the wrong decision and its breaking my heart. He loves my kids to bits and that's wonderful but I would like us to have a child together of our own but he says my kids are enough to handle and they are enough to try to cope with. Yes raising children may be a challenge but it means something to me to have a child with him and it hurts alot that we can't because it is just more punishment I get for being with my ex who walked out on us.

I know I already have three kids but I love it and could easily have more. I just feel happy with kids and babies around. My youngest has gone off to school and I feel like it just isn't that hard. I feel hurt because despite the excuses I feel like he doesn't want a child with me because he thinks I am a bad mother. Its not just that since we moved in together he just makes less of an effort at all. He isn't even a little tiny bit romantic and I don't want to hear oh my husband doesn't take me out or whatever. I mean he doesn't even call me beautiful or bat an eyelid when I take my clothes off. I really doubt he will ever make the effort to marry me and I feel hated. I just want to leave which is going to cause upheaval for my kids but I don't know how to fix this. I think it just feels like time to give up. I have never been one to quit on a relationship but the stress is too much. Can this be fixed or is it broken for good?