1) use a cast iron dutch oven or other heavy pot and use more oil
2) do not drop fish in, rather gently lay fish in slowly so batter has a chance to cook (get a crust) befor it hits the bottom of the pan
3) use a non stick pan
4)use bread crumbs instead
5) if fish sticks, let it be until you can see there is a nice crust on it, and with a spatula try to scrape fish off the bottom of the pan.
6) do you flour the fillets before the wet bater? simple question, but i really don'y know your cooking style.
steve, if you are doing a batter (beer batter or tempura) you really need to fry in a deep pot filled 1/2 way with oil (3 inch min i would say) and follow step suggestion 2