When you Pan fry just dont get it to hot(unless your making blackened redfish),Id suggest staying under med-high heat...but get the oil a little hot before you fry,test it by throwing a pinch of batter in it,make sure it sizzles a bit but if it browns real quick then turn it down.Id shoot for between med and med high heat.
Not sure which fish you have,or the size of it but you pretty much just fry until golden brown..depending on a few things like type and size of fish,fileted or whole etc...aswell as what batter you plan to use.
I deep fry mostly but pan fry if Im encrusting with nuts(pecans),or using bread crumbs,or just frying a small amount.
If you are losing your coating it is because you fish is to wet (I know fish like water) when you bread it. Take a piece of paper towel and pat you fish dry before breading it. Then dredge the fish in either flour or cornstarch shake off excess dip in egg wash and then in bread crumbs. Or if you want just light coating skip the egg wash and bread crumb step. Put fish in a hot pan with hot oil. It will stick to both a cold pan or soak up a lot of grease if the oil is cold. Shake the pan for about 10 seconds after putting the fish in (tip from Alton Brown) helps it not stick also. Then let it brown until you are ready to turn it. Only turn it ONCE.
My mum's from Newfoundland and her whole family were fisherman so she cooks a mean piece of fish.