BTW, there are places in the world that no one drinks the tap water as it is know to carry parasites. Even here in the US in some rural areas, no one drinks tap water. I was infected with a parasite at a family reunion that was held on a farm. I didn't drink any water as I knew better there--- but ate some fruit that had been washed in the water. Got a parasite . . . me and 72 other people (NO JOKE . . . we all ate that dang fruit salad and we all got the parasite . . . my husband and son too!).
good luck
I'm curious where you are from. I do know that in some places that water systems are known to have parasites in them. However, you wouldn't get that from the water going into your nose but rather from drinking it. If it went into your mouth and you swallowed it.
Agree with nursegirl that it sounds like you are having great anxiety that is based on a fear that is unlikely to actually happen. And if it becomes obsessive -- I'd look into OCD. But generalized anxiety can also cause great fear over something irrational.
What are your options for doctors or psychologists in your area?
This is an irrational, unrealistic fear. Have you sought professional help before? Been diagnosed with anything (maybe like OCD)?
Like not, that's where you need to start, with the professionals.
Shower water is normally clean, as tap water, clean enough to drink. I have never heard of anyone contracting a disease from pure shower water. If you are sick, I would think it due to some other thing. See your doctor. - Blu