I kept it private for the most part. My husband was the only one to know for quite sometime. Once I was approved I then told other members of my family and a few very close friends. Today if somebody asks I have no problem telling them my story, but I don't volunteer the info. The ones who do know have been very supportive. I think its a personal decision.
I was having headaches when i was weaning myself off caffeine! By the time I got to the pre-op diet I was doing ok. Are you getting enough Water? Dehydration can lead to headaches. I hope it gets better for you! Good luck with your surgery!!