I'm wondering if any of you have noticed that you're able to handle certain social situations without symptoms one day, but maybe suffer a setback/trigger symptoms in a similar situation on a different day?

Reason I'm asking is because about a month ago I went out to a restaurant with family and friends. We sat on the patio and hung out for about 2 hrs. There was talking and background music, but I didn't suffer any symptoms besides being tired afterwards.

This past Saturday I went to a party at a friend's house. There were around 30 people there. There was no loud music or tv's, but moderate noise from people chatting. I didn't talk to many people, tried to stay in the rooms with few people, and basically was pretty mellow. I didn't drink any alcohol. About an hour into the party I felt a mild headache coming on, but it wasn't too bad. I left after 3 hrs.

I have had a horrible headache, increased dizziness, and sensitivity to light ever since the party. I'm wondering why I was ok going out in a social setting a month ago, but not ok this time. It's not necessarily an apples to apples comparison, but both settings had moderate levels of stimulation. Feeling frustrated and sad because I thought I was slowly getting better!