Has anyone been In a relationship and having trouble with there in-laws...

I got two children with someone else and I’m currently pregnant with my partner baby... he had took on my other two children as there father don’t bother with them so my children look at my partner as there dad... I’ve been with my partner almost a year In March and we currently live with his mum... I’m afraid to comfort her about her telling about her trying take control of my two children... like my partner just sits there and don’t say anything and it’s getting to a stage where it’s making me depressed all because he doesn’t want upset his mum all because she having issues with her other children...

Not only that she always blame my oldest daughter for everything but let my youngest get away with everything yet my oldest will be 3 at end of February but my youngest be 2 In September so there not far apart from age it’s like one rule and a different for the other... I don’t want be around her once my baby is born because we all know what going happened she take over all because she can’t see her other grandkids anymore due to reason

I really don’t know what to do 😓😓 every time I tell my partner we end up arguing but my midwife and health visitor and my mental health team all said it best we move out so we both agree to that but clearly his mum trying keep us to stay all because None her other kids bother with her or help her but they all said my partner attention needs go on me and my kids now