Chas
You will get the hang of it when you stop trying and stop freezing up.
It is really strange how one bad experience landing creates a mental block.
I can remember from my motor racing formula ford days how we had a very short practice session to set our qualifying fastest laps.
Looking at the lap times and on the whole they would get faster until you overcooked and scared yourself.
Then the Lap times would drop off and take a whole load of laps to build back up to speed.
One very quick guy used what he called "mental override" to prevent that drop off in lap speeds following a scare.
If he scared himself by nearly loosing the car or a spin he mentally over rode his fear or caution by planting his right foot even harder and it worked.
What I am saying is throw your fear away, swear at the aircraft do any positive self talking to get yourself out of that grip! relax dont care and it will all come together.
Finally get a decent instructor
Pace