The First Real Cold

Miles got his first real cold. It lasted for over 10 days and he spiked the first scary fever of his little life.
We ushered in the first hours of my first official mother's day, like some cruel cosmic joke, in the ER as he woke with a fever of 105.2. Now on antibiotics, he's doing much better.
But it led me to wonder what I would do if he ever got really sick. Not just the cold and flu stuff but something like cancer. Just dealing with his little cold made me feel helpless. He cried for almost every moment of Friday, would cry when he coughed, when he woke with raging fever, when he couldn't eat because he was too stuffy. And he looked to me with those beautiful eyes and asked me to help. And all I could do was hold him, try to nurse him, try ineffectually to reduce his pain a little.
Is this the ultimate lesson of motherhood? To let go of trying to control things? To accept that we are truly helpless?
I had more insight about this a day or two ago but the exhaustion has wiped my brain clean.