My 2c...
Landing is hard. I had a lot of trouble making good landings when I did my tailwheel conversion. I switched to a different (much better) instructor and in three lessons I had nailed it and was checked out to solo the Citabria. Even if there is absolutely nothing wrong with your present instructor, a different viewpoint will help.
It's impossible to make a good landing when you're tense and stressed. Unfortunately it's a very stressful thing to do... In my tailwheel conversion I got into that state, I was practically in tears of frustration before I even got in the aircraft. Changing instructors fixed that.
One exercise you should definitely try to do: not landing. Descend to within a foot or two of the runway then with just a little power, hold that altitude for the length of the runway (well, not if you have a 12000 foot runway). Obviously your instructor needs to know what you are doing and probably to show you.
It is very helpful to have the instructor demonstrate something while you follow on the controls. This is very different from yelling "your aircraft" when three feet off the runway.
Hope some of this large collection of advice helps...