Lisa,
I'm sorry you feel so bad. I have had several accidents that I feel contributed to my fibro. The first was a car accident; a car failed to stop at a light and slammed right into me, totally my car and injuring my left knee. Now anytime I see someone speeding to a stop light, I get really tense and anxious (and this happened almost 20 years ago). Another accident, I had a ceiling fan fall on me. The fan was spinning on high speed (it was older and very heavy), it spun right out of it's base and dropped on me (I was standing right under it). The blade struck my right eye brow and split it open. The fan bent (I have a hard head) and I was left bleeding and 30 minutes away from a hospital. Well I lost a lot of feeling on the right side of my head and it has taken years to recover but I still can't stand under a ceiling fan without getting very tense. My point, maybe stress and tension from the memory is bringing on the flare. 
Now that I think about it, I do flare every year on the anniversary of my parents death. My father died 14 years ago this November and my mother will be 6 years this January. I do have extreme fatigue and pain in the days leading up to the anniversary. So I guess I would say yes, anniversaries of extreme stress do send me into a flare. Stress is not good for FM and I haven't learned how to avoid it yet.
I hope you feel better soon, try not to think about the surgery. Happy thoughts 
.
Meggie