Family members and pregnancy

A few months ago my husband and I moved in to help my mom out. Since my father passed she has become a bit of a hoarder. Refuse to get help. So we came to help

Clean the house up for her!

Everytime I bring up something about us having kids etc..she always has something bad to say. My sis in law was over and she asked if we had plans for kids and I said not plans exactly but we want them soon and here comes mom from around the corner saying you better have money to add an addition on the house because there is too much stuff here as it is. That made me feel like shit. She's rather have her trash than her first grandchild. She has always said dot have kids blah blah blah because I think she regrets having them I guess. Well we're pregnant. Very early just found out. I am beyond terrified to tell her. I know she will probably want us to move out which honestly I want to anyways because she won't let us clean her shit up. She freaks out even when we do dishes. Afraid we're going to throw something away. I just can't raise a child in this mess but I'm also so sad she's not even going to happy I'm giving her her only grandchild. She's just going to yell and scream and complain because that's all she does. Since my dad passed she's been miserable and wants to make everyone else miserable. I'm just so sad that I'm this scared to tell my mom what I know is good news. Makes me feel bad for finally getting pregnant. I'm injured just now healing and trying to go back to work in the next few weeks so it'll be awhile until my husband and I can afford a place. He wants desperately to stay because we'd get the house and land and I'd love to raise my kids where I grew up but idk if it's worth it. I'm supposed to tell her soon and talk with her that if she doesn't let go soon etc then we are leaving. Also leaves my little brother here to deal with it all and I feel awful about that. He has two more years of high school and I feel like I'm abandoning him to this mess. I'm so stressed and I can't stop crying and I just don't know what to do. I shouldn't be this upset I should be happy. Idk what to think. Any advice?