I'm not at all versed in this area of instruction, but I am sure there is a whole world of psychology associated with discomfort in water and it probably goes back to very early associations if not survival instinct itself. Hopefully those with more training will pitch in, but I am quite sure that instruction to stick with it, and expect that it will come, is ill-advised.
I believe there are methods to re-learn your relationship with the water. Again, not experienced here so I don't want to steer you wrong, just give you encouragement to keep up the search. All my best to your quest!