Lots has been said on here. I'll add just a little - as a humble PA28 pilot.
This plane flies like an airliner. How many consistent landings have you experienced as a PAX in the back of a 737/A320 etc? I remember sitting in the jump seat of a 737 one night, going into LHR. After a relatively heavy landing, during which several overhead locker doors apparently opened in the cabin, the captain turned to me as we turned back on the taxyway and said 'The good thing about heading back this way [the opposite direction to landing] is that we can watch everyone else stuff it up!'.
The instructors at my flying club are mostly retired airline ATPLs with many many years of experience. Their landings in the PA28 show a degree of consistency, but are far from 100% consistent. The best advice one gave me one day was: work the throttle, keep on top of the speed and approach path, and keep working for the landing. It might fly like an airliner, but it doesn't have the inertia, so you have to keep adjusting [small adjustments - if it's a large one - go around], again and again.
Don't be too hard on yourself. As you gain experience, sometimes you will grease it on, sometimes you will land harder and sometimes you will bounce a little. If you bounce a lot, go around. If you are running out of room, go around. Either way, the incidence of messing it up will become less and less, but there will always be that one. I say again 'go around'!
HH