baby not sleeping

WHY WHY WHY. i’m losing my shit. my daughter is 1 month old & she WILL NOT stop fighting her sleep. i do not let her get passed her wake time but she fights it so obviously she’s getting overtired and i try everything and yet she still fights it for HOURS. i do not know what to do anymore i’m am losing it. i have a 1 year old that needs me too and i’m here with his sister all day because she’s fighting her sleep ! help me. give me advice