Adam27 mate you are not alone, I have been driving rigids 23 years and this year started on the bendy trucks and even though I walked my test in the real world its completely different. I have struggled too but what helped me was speaking to my manager who put me in the yard for the day shunting with the a guy with 35 years behind him what a difference, just listen to what your being told and do it over and over again. He walked at the side of the wagon telling me right hand down left hand down get behind it etc. Have a word with your office and see if you do the same.
I’m still struggling but each time I reverse I get better, the yard I work in we have to jack knife the trailer to get it on the bays its a bloody nightmare. We have goods in guys coming in with 30 years experience and they struggle at our place.
Most of all don’t let other drivers watching you put you off no one is thinking “look at that idiot” we were all new drivers at some point.
Forgot to add our shunter has a saying " Don’t be a c*nt take a shunt "