Sunfish,
The CAA & FAA (as well as CASA I would think) has strict guidelines for flying under the influence of everything you mentioned, and the best checklist can be summed up by IM SAFE:
Illness
Medication
Stress
Alcohol
Fatigue
Eating
A negative response to any of the above pretty much makes you unsafe for flying (while the condition lasts). Your post indicates that you seem to have ignored or been unaware of at least three of the above (Illness, medication and alcohol) and probably stress and fatigue as well if you factor in the side effects of the cold. What makes this even more dangerous for yourself is that you were doing aerobatics.
Frankly, I think you should consider yourself lucky to be alive. I agree with Davidt, reading
'The Killing Zone' would open your eyes.
If you think I'm overexaggerating, just think of how the CASA accident report would look if you'd crashed. Specifically, what would their conclusions be?
Bottom line, become more aware of your physical condition before strapping on an aircraft. Ground yourself for illness, medication, stress, alcohol, fatigue.
Confab