I've been using 4# test and fishing from banks like you so these are things I've learned from experience. If the fish swims into cover you can always try giving him a little slack line. The fish usually will free itself enough so you can regain control and pull him into the open. Remember, the fish is going to want to go the opposite way your pulling so try pulling him into the weeds and he might surprise you and head for the open water. Hope that makes sense.
My motto is, hook the fish then worry about what to do with it. At least your hokking a few 3-6ers, my biggest this season was 19" whatever that comes out to. :