Is there a word that conveys an extreme distaste to the point nearing phobia?

Solution 1:

Consider loathe

to feel intense dislike, disgust, or hatred for; abhor; detest

If you need a noun, loathing.

Also

  • abominate
  • abhor
  • execrate

Solution 2:

I think the word you need is 'aversion'. It is less severe than phobia, but it is bad enough that professionals offer 'aversion therapy' treatment.

Solution 3:

Swimming in fresh or seawater repulses me

would also fit

Origin

late Middle English: from Latin repuls- ‘driven back,’ from the verb repellere (see repel).