My fiancé might leave me 😭

I've been so on edge lately because of everything going on. I'm so scared. My mom hates him. For no reason. But she always finds a way to work in some shit talk about him in every conversation we have. I can't even tell her were engaged beside she would flip and I can't deal with the stress and a newborn preemie baby. But he's a great guy. He's a GREAT dad. He's everything to me. He tries so hard for me and my daughter. Like God sent him to me and gave us a perfect gift. His family is so loving and accepting of me and our baby. My mom hates them too. Calls him mom crazy and weird just because she loves us and makes sure we're okay. His mom is a angel in my life. An ANGEL. But my fiancé cannot get over my moms shit talking. And it really bugs me too. I want to stand up to her but I know she'll hate me and shun me and I need her support. My dad pays child support still and she pays it to me. She'd stop giving it to me. And as we'd be fine without it, it's still so helpful. I'm on her medical insurance, and car insurance because it saves me almost $100. I'd lose that in a heart beat. Than we would be struggling. Well my grandma comes to town tomorrow and I was going to spend the night with my mom and grandma and come back home, well he went through my texts to my mom, I let him, and again he saw her shit talking him. He told me not to come home. He told me to stay at her house, and that he's not even sure he wants me loving with him any more. It absolutely broke my heart hearing those words. I have nothing to do with my mom talking shit. I either ignore it or counteract with something wonderful about him. Idk what to do. I feel like eventually he'll leave me. Please help. Please give me advice. I don't want to lose him, he is my world. And I don't want our daughter to have to have sperate house holds her whole life. I love him. I need him.