Anne, NoM said she was "disappointed and annoyed and down about it" - referring to her friend not turning up.
NoMercy, I am glad you're feeling better today. It could be down to something as simple as you being overworked, perhaps? You say you had a very busy day and didn't eat until 3pm - and even then it was only sushi. Sometimes, when I miss meals, I get shaking and this tends to increase my anxiety levels. Most of the time it stays at just that, but on the rare occasion it escalates, then it can turn into a full-blown anxiety/panic attack, which then makes it impossible to eat - which could be the reason you struggled to eat.
They say there's always a reason/trigger for anxiety/panic attacks, but ten years on and I still don't have the foggiest. Certain things seem to make it worse, stress, tiredness, hangovers, etc. Now I just try to ride them out, rather than spend my time analyzing the situation and trying to find a reason - as there often isn't one!
I wasn't aware of your recent relationship breakdown but, going by the words you have used to describe this person, I doubt very much this is the reason for your recent anxiety issues! :-)