I believe that what might help is specific exercises with you doing the controls, not the instructor; and to start with, just doing very gentle pushovers until you feel comfortable with that level of slightly reduced g. Then progress to a bit more until you are comfortable with that. Etc. etc. Most people seem able to acclimatise gradually with repeated experiences.
The worst thing is to have an instructor do it to you, and to do it with so much reduced g that you cannot stand it. I do not think you will ever acclimatise to it that way, and it will be a totally dispiriting experience which will condition you to hate it.
It is essential that you can cope with, and distinguish between, stalling and negative g. People who couldn't have died.
If you cannot crack it, flying is not for you – you will be a menace to yourself and anyone you fly with if you panic.
I agree with the tight strap advice – it should help you to feel secure.
Just my 2p’th.
Chris N
Last edited by chrisN; 8th April 2013 at 22:29.