Well you did say that you flew pressurised to ground level. So unless you were flying the Ekranoplan (unlikely) I think we wonder what the difference between your actual alt and your cabin pressure was.
I think Hikoushi makes a valid point; it's one thing and level of risk to board a pressurised aircraft as pax if you have a cold/flu etc; it's quite another when you are at the controls, and even more so when both have the same condition. Competent carriers should envisage this in their SOPs.