can pressure at the roof of your mouth(hard palate) be a sinus problem symptom?.also if you breathe in through your nose and feel some pressure can that also be one?

You have a variety of sinus cavities that can be infected. Depending on where the infection is you can have pain in any part of your head or face. My infections usually end up in my teeth and gums. the more severe ones are horrible throught my entire face. if you cannot get the infection to break with sinus medication, eg. Sudafed or something similar, you may need to call your doctor and get a prescription for an anti-biotic. Good luck to you.

i heard the flu vaccine can actually cause problems if you already have the flu, is that true?

No, do not get the flu shot. the flu shot exposes you to small amounts of infection so that your body learns to fight them with the appropriate immune response. If you already have the flu, it is too late. Buy tissues, tea, sudafed and tough it out.