Sorry to hear about your problem with HPT.
Do you know that you can go to the library and practice the HPT by using the cd roms that they have.
This is what I did over and over again until I sussed when I was meant to click.
I was actually clicking too quickly at first -apparantley because I drive a motorbike my anticipation was too good which is what you learn to do to avoid
mishaps with some car drivers when on the road.
As youve probably realised by reading responses, the whole thing does not represent actual driving and is a matter of learning to click when THEY want you to.
Good luck on retest. 
I have the dvd 
I blame it on them having PCs from the 1980s that took 30 seconds to register me clicking.
Retest booked for this coming friday. 
The HPT test is such an utter waste of time, it benefits nobody at all, just the DSA making more money, ■■■■■■■■
Hoorah, amazingly I passed my test, start my rigid training on 4th June
Well done mate!!
That’s the stupid / daft / waste of time bit out of the way now!! (In my opinion, anyway.)
Good luck with the training too. You’ll love it.
Looking back, I wish I’d just sat back and enjoyed it rather that being so bloody nervous about it all!!
Still - you live and learn.
I pass through / go round Norwich periodically (depending on whether I take a wrong turn or not 
) on my way to M R Ellis Timber. They are on the A140 Cromer Road. I’ll start flashing at any LGV training motors I see - probably scare all the learners to death!!
If you need any help with anything - please ask.