What should i do or take to relieve sinus pressure?

Nasal spray: Flonase/ nasonex (mometasone) type of nasal spray will relieve you in 15 mins

Sinus Pressure: A simple non-medical way is to use salted water or saline sprays. Afrin (oxymetazoline) or equivalent can be used for immediate relief but should only be used up to 3 days in a row. I find real Sudafed Immediate release can help, but make sure you have a valid ID to pick up at the pharmacy. I hope this helps.

Sinusitis: This may be sinusitis or sinus inflammation. Allergies may be one cause but there can be many others. Mild symtoms may be relieved by over the counter saline sprays, irrigations, or decongestants. OTC pain medications may help as well. See an ENT for an evaluation if recurrent.