You could try the antibiotics and see if they help, and if not or they make you feel worse, just stop them immediately.

Either way, if you're not already, make sure your diet is completely sugar free, yeast free and gluten free. Candida can cause headaches and sinus problems, especially in mercury toxic people.

It could be caused by mercury too, or even root canal toxicity or cavitation toxicity. Regardless, diet is crucial.

You have every right to try the antibiotics in hopes it might help if it can wipe out a possible infection caused by something other than the things I mentioned. But if mercury or the other stuff is causing it, then they may not help, and coudl make you feel worse (but just go off them if that happens).

Sorry I'm not much help. I have had problems myself with pressure headaches etc and did find the candida diet to help that immensely and probably saved my life. Things like sugar and wheat are some of the worst things a mercury toxic person can consume.