If you knew what we were getting into when you said 'yes' to motherhood, would you still do it? I've no doubt had Mary seen what lie before her, she would have done it anyway. Her faith in God was that strong and her love for Christ the moment the idea of Him was presented to her, became unshakeable.
One more thing: Mary felt the same joys and pains of motherhood that you feel. She knows acutely all of the ups and downs. She also knows that when you say 'yes' to God, great things happen. And that her Son will be there with you through it all.
Prayer: Dear God, I willingly and openly say yes to you each day and thank you for the gift of motherhood. You know perfectly what my children need and when they need it. Help me to be the mother you desire me to be. Mary, my mother, pray for me. Amen.