I think you must have had an infection, Judith, probably contributing to your problems up there. If it had been entirely due to altitude sickness (High Altitude Pulmonary Oedema) (or HAPE as it's called with the American spelling) the symptoms would have cleared rapidly after descent. It's a pity it spoiled your enjoyment of the actual climb, but wow, well done for making the summit anyway.
As a matter of interest, how many days base-summit, and what's the approximate altitude at base (start of trek)?