Im sorry I left without you last night, but I told you to meet me early because

the presentation started at 8:00. I had worked / had been working to get
it right for years, and I didnt want to miss the beginning. By the time I finally
left the cafe where we were supposed to meet, I had had / had been having five
cups of coffee and I had waited / had been waiting for over an hour. I had to
leave because I had arranged / had been arranging to meet Katherine Stern in
front of the gallery.
When I arrived, Katherine had already come/ had already been coming inside
and she was talking to the first guests near the entrance. She was really
angry because she had waited / had been waiting for more than half an hour.
Katherine told me you had been / had been being late several times in the
past and that she would not make plans with you again in the future. And in
the future, I suggest you be on time!