I'll be another to say that goggles were KEY for both of my kids. Also, this is advised against by many, but for my more anxious child, swimming in a life vest helped acclimate her to the idea of deeper water and understand how her body worked in water.

BTW, my 5yo still hates having his hair washed but is an amazing swimmer. (He even swims butterfly. *I* can't swim butterfly.) Don't ask me how that works!!