My 11-month-old son recently found the courage to let go of the couch cushion and take a step on his own. As he went for the second step, he fell hard and hit his little head on the floor of our living room. I rushed to scoop him up, but instead of collapsing into my arms, he reached for his dad.

Over the past month, my heart has broken dozens of times as my little boy spurned my love in favor of my husband.

It happens every morning during breakfast when my husband strolls out of the bedroom for his coffee and our son instantly smiles when he enters the kitchen.

It happens each time my husband goes to take our dog outside. Our son immediately starts crying and crawls toward the door after he leaves.

It happens at bedtime after I get him in his pajamas and begin our nightly prayer, he squirms out of my arms and into his dad's for the final kiss and tuck-in.

There is a logical part of me somewhere deep inside that understands this is just a phase he's going through and it won't last forever. My husband, too, with deep sighs of exhaustion, regularly points out that for the first 10 months of our son's life, he only wanted me.

Yet there is a louder, uglier part of me that is filled with jealousy and resentment. An emotional monster that causes me to feel irritated and, eventually, disengaged, each time my son reaches for his dad. It feels devastatingly similar to sharing your feelings with someone and being rejected, except it happens over and over again, every single day.

However, it's worse when it's your child because when you have infinite love, there are infinite possibilities for a broken heart. For those first 10 months, I was my son's primary source of comfort. I could ease his tears and soothe his pain. Now, each time I take him out of his dad's arms, I become the primary cause of his distress.

Especially during the first months after his birth, as I walked our son back and forth in our small apartment trying to lull him to sleep, I would seethe with anger at my husband for not helping. I would imagine going into our bedroom and dropping a bucket of cold water on him or blaring talk radio in his ears—anything and everything I knew that would simultaneously wake him and irritate him.

Many nights, in the rare moments of quiet between feedings, I would lie on the couch—restless and exhausted, in a strange type of new parent purgatory—and I'd write out my feelings. These letters were full of self-loathing, doubt and insecurity. Sometimes they'd be directed to my husband, full of the hard-hitting and mean-spirited one-liners that only come from the darkest depths of desperation. I'd write about how I felt like a single mother and how my heart hardened toward him every night he slept through our son's newborn cries.

It's only now that I understand just how difficult the flip side of the coin is.

Each time I got angry at my husband for not holding the baby so I could sit down for a minute, I never noticed the hurt on his face when our son immediately reached back for me.

Every night I felt disgruntled as I rose to the sound of a cry through the baby monitor, I didn't notice my husband lying awake—wondering what he could do to help.

All the times I dismissed my husband's attempts to give me a break because he "only made things worse," I didn't realize that he was trying to create the type of bond I had with our baby since before his birth.

I don't know how long my son's "dada" phase will last. A baby's attitude and preferences can shift instantaneously, as I've come to realize over the past year. And although it continues to weigh on my heart every time our son chooses his dad over me, I'm working on being understanding and also thankful.

This challenge has forced me to see things from a different perspective and appreciate the unique challenges dads regularly face. Eventually, our son will reach for me again. And when he does, I'll be able to smile gratefully at my husband and soak in every ounce of love that I had once taken for granted.