One thing that stood out to me was that you felt humiliated. There really isn't any reason for you to feel humiliated. I'm sure the girl at the top of the stairs was happy to not have to go back to work right away and the other girl sounds sweet - she certainly didn't fault you for being slow, and if she did, who gives a carp! You kept it together and made the trip slowly but surely. Please don't be embarrassed!