I have oversensitive "touch" sensations. I don't know the cause
   honestly; hiding it mostly my whole life so far. Certain
   sensations, like the cold one feels after a shower, sends me
   into panic attack fight or flight mode that lasts for 20-40
   minutes afterwards.

   Over the years, I've found ways around it. I used to go for a
   run right after a shower, to break a sweat and warm up again, in
   effect, "running away" from myself. The nerves all over my body
   were SCREAMING at me. "PAY ATTENTION!", like millions of voices
   that won't stop.

   Nightmarish but just something I coped with.

   But over time, I learned other ways to handle hygiene. No-rinse
   shampoos and body washes, or showering dry. [various powders get
   rid of skin oil and dirt as well as water; it just has to be
   collected and moved away from the body, whatever the method].

   So I understand hyperactive nerves. Somehow I've managed to stay
   off drinking or prescription drugs, although it's been tempting
   at times. I don't have the same issue as you, but I know the
   nerves of the body are very strange things indeed.