To get them used to having water on their faces, we use little squeeze balls or puppets, and spray a little water on them so they can adapt to it slowly. If a child is traumatized from other lessons that they have taken, it could take a while for them to calm down while they are in the water, and get used to it. From my coaching experience, it takes on average 16 lessons to calm down a frightened child, and 32 lessons if they have been through extremely bad, forceful lessons. Be patient with them as they adapt and have fun with them. And you have to be willing to work a lot of hours.
Sacrifices have to be made because someone has to do the job.
You have to find the market for the sport and fulfill the need of that market. There is a huge market for lessons on weekends and so you have to be available to teach then. The same thing goes for lessons in the evenings. That is more convenient for working parents and so you have to arrange your schedule around what works for them. Also, you can t teach for the money, the rewards are found in seeing the kids excel and learn the sport.