As others have said, it sounds like you are looking just in front of the nose when you try to land - commonly leads to balloons and hard touchdowns. You need to look at the end of the runway when you start flaring. Is it trimmed when you cross the threshhold?
And don't think YOU are landing the aircraft. Pilots don't make GA aircraft land. If you have in your head that you have to make the aircraft land, you will always have trouble. All you do is put the aircraft in the right place and wait until IT is ready and lands itself. When it runs out of energy and is ready to land, it will land. Try and force it to happen, and it will bite.
It will happen, just relax. If you think your instructor isn't helping, ask to do a few circuits with the CFI. They'll sort you out.