I am working on the mental part of it. I do pretty well most days holding it at bay by simply reminding myself that it's not REALLY inhibiting my breathing and/or over-focusing on some other activity.
Ironically-I can hold my breath and that doesn't bug me at all.
I believe it started when I was 3 or so. I don't recall the incident at all, but my family was hanging out with all of the extended family (LOTS of people) at my grandmothers (in Missouri). Her property has a pond and the kids (myself included) were playing on a hill of dirt by the pond. We got "smart" (or dumb as the case could be made) and created a "slide".
In the sliding on it-it got closer and closer to the water itself. Lucky me-I was the "breaking point" and slid in.
The hill was by the deepest side of the (very muddy you can imagine and therefore murky) pond.
I didn't know how to swim.
Obviously as I'm here typing 30+years later, they did manage to find me under the water (my father and another woman). Unfortunately by that point I wasn't breathing. Fortunately my dad was a perimedic and knew how to-and did do mouth to mouth.
Again unfortunately it was MILES from the nearest town. Someone (not sure if it was my mom or some other adult) drove to meet the ambulance after someone called 911 while my dad worked on me.
All I know about the end result is-obviously I lived and there's no brain damage.
But from that point on my parents kept me away from water. In middle school I went with friends to a pool. Being a very well endowed young woman (DD at that point but only a size 3 jeans) I tended to attract boys attention. The pool was in a local highschool. One of the older boys that we didn't know pushed me into the deep end. A friend pulled me out (thankfully quickly enough I WAS still breathing and no complications).
That along with a near scare at church camp at age 13 or so and I was pretty much "cured" of any desire to be near water and the phobia was well entrenched and controlling my life. I wouldn't wash my face in the shower or dunk my head under in the bathtub. I flat refused to go NEAR a swimming pool and I (this one is positive) NEVER entered a boat without a secure life jacket. I also never went in "open water" unless I was with one of VERY FEW trusted friends who I was CONFIDENT wouldn't allow anyone else to TOUCH me. I would wade in water then, and only then.
When my daughter was 3 (I was 19) I put her in swim lessons-because I didn't want her to be like me in that area. It required I enter the swimming pool building and that was traumatic for me. But listening to the cries of terror from her (which was crazy in a way-because the kid LOVED to hold her breath under water in the bathtub and I always let her and promoted it even though it chilled me to the bone to see) made me feel guilty.
Trying for the "mature" solution. I asked one of the lifeguards-who was also a friend to give me swim lessons one on one. She agreed.
It was a long trek-about a year. But I learned to swim (if not attractively-it IS functional
I actually learned that it was LESS distressing for me to dive UNDER the water, holding my breath-and swim for however long, then come up for a breath, and go back under
trying to do something like the front crawl-which I still can only do if there isn't a "crowd" in the pool with me as it causes anxiety issues.
I can dive off the diving board (low preferably as my large chest makes any type of dive from the high dive painful) and swim to the other end (beneath the water) and rise as graceful as you please to the top.
I can sit under the water with my 9 year old on the bottom of the pool with my eyes open (and his) and slowly blow out air bubbles to see who can stay down longest.
But I don't handle people's hands or arms around my neck (except Maca's or GG's at specific times which is even odder actually) and I obviously DO NOT do this sensation well either.