Hi BF and welcome back...
...although I am sorry that it's due to a new worry.
However, the concern you have about
the water borne amoeba is only your anxiety acting up, as this is only found in contaminated natural bodies of water...
...and even then, extremely rare.
You can not contract it from tap water.
Rest easy tonight...you are going to be fine.
If you need more reassurance...work through your worrisome thoughts with the Therapy Worksheets from our Resources at the top of the main forum page here.
"Courage is not the abscence of fear, it is feeling afraid and doing it anyway!"
"Worrying does not empty tomorrow of its troubles...it empties today of its strength."
Corrie Ten Boom
Panic Syndrome recovery due to CBT