Hey Paul... Welcome to the forum. There's really not enough information in your question for anyone to give you an answer, I think. Headaches and dizziness could be any number of medical issues, and could be caused by numerous factors including the atmospheric pressure. I get those things often and I don't have fibro.
I'm sorry that you're having the headaches and dizziness. If you're only asking if those things can be signs, I'm sure someone will be able to answer you. (I don't know off-hand.) But since you asked if it's fibro or something else, it's impossible to know without testing. Have you been diagnosed with fibro or suspect that you may have it?