Sorry to rain on your bonfire chap!
If ground rush is the problem, then maybe using a helicopter with a little more inertia in the rotor system for some confidence building hours may help. Why not go and do a few hours of autorotations in a Schweizer 300 and then come back to the robbo when your more confident in your ability?
There are pleanty of high-time instructors around here that may want to voice an opinion on this...
CRAN