"Aw, he's so tiny!" Those words crush me every time I hear them.

It's different when I call him my tiny peanut, I'm his mother. I don't want to hear others tell me how small he is. Trust me, it hits me every single day when I put him on the scale and hope by some miracle he gained 6 ounces overnight. Shockingly, that has never happened.

My son is in the 3rd percentile for weight, also known as failure to thrive. Those words crush me every time. Failure. Only seven letters, two syllables. Immeasurably painful. I can't help but feel like I'm failing my son despite trying literally everything I can to help him gain weight.

Three years ago, I gave birth to my first son. He was also a small baby, usually in the 14th percentile. I spent my maternity leave agonizing over weighed feedings, topping off with bottles, and counting ounces. I tracked every feeding meticulously, every weight check went into my app. I tried to figure out how much he would need to gain by a certain date to hit some arbitrary milestone. By the time he was one, he had climbed to the 40th percentile and I swore it would be different with my next baby. I swore that if things weren't going well, I'd just go to formula next time instead of breastfeeding no matter how much I loved it.

The universe has a cruel sense of humor sometimes. Things have definitely been different this time. This baby had no problem nursing and it literally never once hurt. This baby was hospitalized before he was 4 weeks old. This baby has endured two different tongue tie revisions. This baby has suffered so much pain due to reflux. This baby hates the bottle despite being given one since he was 6 days old. This baby acts as if formula is poison.

This baby is failure to thrive and I have failed to stop it.

The guilt is unreal. Maybe if I hadn't tried to breastfeed and just did formula. I suspected with my first that my milk wasn't very fatty so why did I think this time would be different? Maybe if I'd given up dairy sooner, it would have changed things. Maybe if I hadn't bragged about how well things were going when he was a few days old, it wouldn't have all gone wrong. The what-ifs are impossible to escape.

Almost as bad have been the people who try to help. They tell you how their cousin's baby was just small and they're fine now. They tell you how if you just mix formula with breastmilk and warm it to the perfect temperature and put it in a certain bottle, your baby is guaranteed to drink it like a champ. They tell you gripe water will cure the reflux because it worked for their baby.

They mean well, but they don't know what it's like.

They don't know the worry that comes from realizing your baby hasn't gained an ounce in 10 days.

They don't know the frustration as you warm up another 3 ounces of milk and try the seventh bottle because somehow this time might work after the other six failed today.

They don't know the helplessness that comes from watching your baby scream at the breast because drinking milk is agony.

They don't know the utter defeat that comes from finally getting enough ounces into your baby for the day only to watch them spit up the entire last feed.

But we're getting through it, together, one step (and ounce) at a time.

If motherhood is a marathon, motherhood to a failure to thrive baby is an ultramarathon followed by a triathlon. It is a test of endurance, patience, determination, pain, frustration and love. While others lament having to buy clothes so often, you learn to celebrate the fact that your baby gained an ounce after almost two weeks of stagnating. While others celebrate their baby sleeping through the night, you plan the optimal dream feed schedule. It is a hard road paved in loneliness and isolation because so few can truly understand it.

I never would have chosen this road and, to be honest, there are many times I wish there was an exit ramp. Still, I've made the most of the journey. I've learned to never take for granted the little wins, like my son drinking 4 ounces and keeping it down. I've learned to find the humor in my son spitting up all over his dad then spitting up all over me right after. Most of all, I've learned to reach out to others, to ask for support and give it when I can. You are not alone in this journey, mama, and you are most definitely not failing as a mom.