Postpartum mental help

My baby is 7 months and I’m struggling. Everything has been smooth sailing but for the last few weeks I’ve just felt overwhelmed and extremely sad. I’m exhausted and i don’t know what to do. I don’t work and i don’t have friends or family and my husband works most days and is always tired so i have zero help. I find myself crying a lot lately while my baby is in the other room screaming her head off. I’m so alone. I’m in the house all day with a screaming baby. I can’t even go pee or find me something to eat because she just cries and screams as soon as i place her down. I have to hold her all day and I’m just losing my mind at this point. I’ve told my husband i need more help with her but nothing’s changed. I’m afraid to tell anyone because they’ll take my baby from me if I’m depressed. How do you guys deal with this? I need to get over it soon because Im obviously a horrible mother. I’m supposed to know how to do this and I’m failing so hard. Please can anyone help