It's OK. It's OK to be useless. It's OK to be sad. It's OK to need help.
Who gave you permission to say those things about yourself? You are God's beloved child, created for his glory and redeemed by his grace. He delights in you. Yes, even now, when you feel you are at your worst, when you feel like a failure, when you have nothing to offer, even now - he delights in you.
This is a hard stage. That is just facts, it has nothing to do with your efficacy or skill. It just is, unequivocally, a tough stage of motherhood.
You can only be what God made you to be. You are only as useful as the grace he gives you at any given moment. If you find that God is pleased to render you useless sometimes, don't despair. Rest.
Nothing you do or fail to do can change the love of God for you, his child. You fight this, and if you're honest, you don't really like this about God. Surely, if you do things right, he'll love you just a little more. But his love does not fit in your hand. You are thinking in teaspoons about a love that floods the oceans. Toss away your measuring cups and drown in it.
The Me I Am To Everyone Else