I screwed up.

I knew it would happen eventually. The doctors and nurses warned me. Other parents I’ve met in the past year with diabetic kids warned me. Even the Internet, with its vast array of information on being the parent of a child with T1D 

(from the official to the personal through the questionable and, thankfully, the reliable) assured me many times over in various articles, posts and pages that it would happen at some point.

I really screwed up.

I’ve got an excuse. It was a bad day after a particularly bad week. The entire family, one after another had fallen victim to a nasty stomach flu. I was exhausted from dealing with a sick husband, two sick kids and a sick self. I was sleep deprived from rotating shifts with my equally burnt out husband to check my daughter’s blood sugars every few hours several nights in a row as her body battled the bug. I was completely worn out from looking after everyone else when what my body (and, I realize now, my mind) needed to recuperate was rest.

And that’s how mistakes are made. But some mistakes are worse than others. And when the mistake is miscalculating how much insulin to give your child, it has the potential to be deadly.

Here’s how it happened. My daughter’s glucose was high, very high, in fact, because, as we’ve learned through the various viruses she’s caught this winter (it’s been a rough haul), the body becomes insulin-resistant when it’s ill.

So that evening, I had to increase her rapid insulin significantly to deal with the excess sugar that was already in her, as well as the dinner she was about to eat.

But I didn’t increase her rapid insulin. I mixed up her doses, increasing her long-term insulin instead. The one that would be coursing through her body as she slept.

Too little rapid insulin (about two-thirds of what she needed) and too much long-term (about double). Didn’t notice. Didn’t double-check. Didn’t catch my mistake at the last second with an “oh thank god I caught myself in time!” Nope. Just drew the shot and injected it into my trusting, unsuspecting little girl.

Her bedtime reading was the first tip-off. Instead of coming down from 18, she had spiked up to 25 (her target is 4-10). At first we thought maybe she was getting sicker, but something just didn’t feel right about that assumption. With the amount of rapid we thought we’d just given her, there was no way her reading should have gone up. It was my husband who suggested maybe I had messed up her dose.

So I went back to her log book, reread what I had written down, mentally walked myself through the process, but still couldn’t believe I could do something like that.

Well, I had. Because when we checked her again two hours later—just to be safe—she had crashed down to 7, proof that the double dose of long-term insulin was starting to do its job. Two hours later, she was still on her way down. Two hours after that, as the insulin peaked, we struggled to get her back in target, pumping juice and protein- and carb-filled snacks into her through the wee hours of the morning until finally, around 4 a.m. we got her safely back up.

Thankfully we realized early enough what had happened. Thankfully we knew what to do about it. Thankfully my husband’s daddy-sense kicked in (because obviously my mommy-sense had taken an unauthorized unpaid sick day and checked on out). Thankfully my daughter sipped through the juice boxes we desperately shoved at her and munched down the snacks we shoveled into her throughout the night, drowsy but uncomplaining.

They tell me it will happen again. The same mistake or some variation. Because we’re human and we’re not infallible, and we have bad days (and bad weeks and bad months and dear god this has not been a good year).

Because sometimes we just screw up.

I just wish that I didn’t hold my daughter’s life in my hands every time I stick a needle in her arm.