I would say the gear you are using is too heavy, the lighter it is the easier to use and the more enjoyable it will be.
I use a 2 - 4kg Shimano Raider rod fitted with a Shimano Sedona 1000 and 6lb braid, 1m of 8lb mono as a leader. Keeping it as light as possible will allow you to cast further and more accurately which will result in more fish. Caught plenty of flatties on this combo right up to 76cm.