I am not sure what sort of aircraft you are flying in however my guess would be either high wing cessna or low wing warrior. A low wing allows a more cushioning effect close to the ground which aids in managing you rate of descent more easily.. .The hight wing cessna does not have the same cushioning effect but tends to float if you above your nominated airspeed. A positive landing is a good indication that you are landing at the minimum possible speed. This is a good sign!!
Remember firstly that in the last 20' you are going from a slightly nose down attitude to nose up. This is a big change in attitude and inertia. Never rush to get the aircraft on the ground. This is a common problem where people feel pressured in getting the plane on the ground. This happens normally due to a case of excess speed.
I have also found that people go straight into the flare attitude as soon as they reduce power. Try and do the attitude changes in stages. Close throttle and then fly in straight and level attitude until excess speed has washed off. When you fell the sink slower raise the nose onto the end of the runway (orange boards). Rush it, especially in a cessna, and you will have a balloon.
The last piece of advice is try doing some flapless landings. These help in an number of ways. They give a good prospective of the flare attitude, keep your feet working hard and normally end up being greasers. Gets the confidence up.
There is light at the end of the rainbow. GOOD LUCK!!!