It's good your getting the hang of it. When I practiced I found a car park and set myself the target of turning consistently within 2 bays. Half an hour later I was stringing them together and turning tighter and tighter. Doubt I could do the same now though.
Yeah, it's just a confidence thing. Once the technique is sorted it's all about practice and convincing yourself that the bike is happy to turn in a small radii.
My problem was not really understanding the technique. When I started, I didn't get the hang of the rear brake because I was treating it like a car's brake pedal and dabbing it gently. When I took some time to practice using the rear brake, I came to realise it was far less sensitive than I was assuming. Once I'd got the hang of it then it was as though the slow speed manoeuvres lost 90% of their difficulty.
I've booked in for another CBT so with a bit of luck I might get through this time! Riding on the road is going to be interesting after having done everything in a car park so far. In the car park, I got up to the giddy heights of 15mph and in a built up space that seemed mightily fast!