Graeme Cooper wrote:

I am getting some tips here, so I guess A full English fry up breakfast
just before would be a bad idea and if I keep my eyes closed that may
help.

Maybe, I've never tried closing my eyes while thermalling... :-)
The most important point is not to move your head. (Not if you're the
pilot, of course!) Opening the vent and let cold air blow into your face
helps, too.

How will it feel doing a loop the loop?

Frankly and disappointingly, not too spectacularly. G-load is always
positive, so you keep sitting in the seat, and it doesn't challenge your
inner ear either, because the acceleration is strictly one-dimensional.
If you close your eyes (as you've intended to do), you will not even be
aware that you've done a loop. That's why a loop is well suited for an
intrepid but unexperienced passenger.