Mama, please reach out to a doctor or counselor right away, what you're describing sounds like it could be postpartum depression, and you deserve real professional help, hindi ka dapat nakakaramdam ng ganito alone. Ang thoughts of hurting yourself ay serious, at may resources kami dito, you can call the National Center for Mental Health hotline or go to your nearest hospital.
I know it feels hopeless now, but postpartum is a medical thing, hindi ka failed mother o wife, your brain and body need support right now. A few of us moms went through something similar, and talking to a doctor changed everything; seryoso, it's not weakness, it's exactly what you need. Your kids need their mama healthy and happy, kaya please, make that call today or have someone take you. You're not alone in this, and this sadness is treatable.