Last night I had a feeling like a bubble was popping in the top left portion of my head, then dizziness to the point where I thought I was going to pass out. That lasted a few minutes, followed by nasea and some chest tightness. I still feel nasea 10 hours later. Prior to this, my sinuses have been acting up, had occasional ringing of the ears (especially the left one) and experiencing more stress than usual. I used to take Zyrtec D, but was advised to go off because my blood pressure had been elevated recently as well. Is what happened sinus-related, or should I be more concerned? Thank you.