As a writer, I get to create characters I love and torture them. As a mother, I get to watch anxiety and irrational fear play mindfuck games with my brilliant obsessive-compulsive teen, while I try not to feel helpless.

I never used to swear—I have OCD to thank for that. (At fourteen, I accidentally let slip one goddamn and was reprimanded with a “Listen here, young lady” tirade I remember verbatim.) But once OCD slithers into your home, you learn to play dirty.

Know thy enemy is the first rule of sharing your child with an anxiety disorder. After I learned that lesson, I jumped into the OCD arena, fists swinging. Which brings me back to profanity….

One of my son’s earliest OCD fears was that he would accidentally swear at me and I would die some horrible death as a result. When we entered into exposure therapy, it became clear my role as OCD coach would include persuading my nine-year-old to bad-mouth me. The day he found the courage to call me an asshole, I glowed with maternal pride.

(I know, living with OCD changes the ground rules of parenting.)

By the time our child psychologist suggested diffusing anxiety with a calming sentence, we were proudly creating fragments of expletives. So we upped the ante. And stole our Om phase from Billy Mack, the aging rock star in Love Actually, who speaks the immortal movie line: “Fuck, wank, bugger, shitting arse, head in the hole.”

I dare you to say that when you’re fearful. Works like a shot of beefed-up chamomile tea.

After we expanded our vocabulary of obscenities and became well-voiced in cognitive-behavioral therapy, we marched through years of exposure therapy and signed up for what Marian Keyes—the fabulous Irish author—calls anti-mad pills.

I refused to quit and I refused to let my son quit. I mapped out exposures like battle strategies, took endless notes in meetings with mental health care professionals, and connived to steal alone time with the psychologist. Eventually, our hard work paid off. OCD slunk into the shadows, my son plowed through a brave new world of firsts—first international school trip, first solo plane ride, and I forgot the shortcut to the psychiatrist’s office.

Then junior year of high school slammed into us with the force of a rogue wave. It’s hard to explain to the outside world what OCD looks like. Certainly not my charismatic son with the kilowatt smile, GPA off the charts, numerous awards, and a perfect score on one section of his SAT. But OCD is like a character in More, More, Said The Baby. Enough is never enough. And the buzzword for junior year is more: more AP courses, more achievements, more college visits.

As the pressure piled up, I found myself scrabbling to manage my son’s stress in the same way I had done when he was younger. (You don’t need a Ph.D. to figure out stress triggers anxiety, right?) But this time he was older, wiser, and more articulate—with a dazzling array of cuss words and a good eight inches on me. And I had to master the hardest parental lesson of all: backing off.

No more fist swinging. In fact, the opposite. I had to accept that I could no longer coerce him into exposures or guilt him into practicing the CBT techniques that were branded into his subconscious. What I could do was listen and understand, and offer unconditional support when he said, “I’m not strong enough to fight back today.” I learned that my son didn’t need to win every time—in life or against OCD. Pulling back to regroup isn’t quitting. It’s accepting limitations and knowing that sometimes less, not more, is the answer.

In many ways, I’m thankful the OCD resurfaced now, in junior year. Because here’s the thing: shit happens. (Really, I didn’t use to swear; I’m a minister’s daughter.) And when shit happens, OCD is waiting to pounce. It’s a fact of my son’s life, and in a year and a half, he’ll be dealing with all kinds of crap by himself in some grotty student accommodation. Thanks to the hell of junior year, he’ll be prepared for that future to include OCD.

Eight years ago, I was the parent hovering in every session with his psychologist; now I’m the person in the waiting room. Before long, I’ll be the voice at the end of a phone line. But that’s the way it should be, because even ELT kids have to leave the nest. For the first time, he’s taking responsibility for managing his own mental health. Me? I’m as proud of him as I was the first time he called me asshole.