It needs to be heard-no where else to say it

I have failed as a mother in every aspect.
My inner demons have become impossible to smother and fload my mind. I've been hopelessly depressed and lost my whole life, but you saved me, you brought me to life. You keep the little flickering light left inside me aglow and was always enough to drown out all the darkness inside. 
But years and years of pretending and hiding have weakened me and I fear one day soon that blackness will consume the light and I can no longer bear living. 
Why was I made this way? Why do I constantly feel hollow when I have so much and more to fill my heart?
I can never be the person I long to be, with such darkness dragging me down. I sob every night and contimplate releasing you from my poisonous presence, you deserve better than me, I am weak and alone even when standing in a crowded room,  pretending I am okay takes every ounce of energy I possess and I'm beat, so emotionally and mentally drained and I would give anything to be that joyous, energetic, care free mother you both deserve, I am so so sorry for failing you.