You could try a little self facial massage:
Place your thumbs, with the nail down, on the area between your cheekbones and your nose. Press and hold breathing deeply through both nostrils (if they are fully stuffed up just try anyway). Let go and breathe deeply through your nose again.
With your thumbs in the same spot press the edge of your knuckle of the index finger on the eyebrow and press down while breathing deeply.
Also at the base of the spine between the neck and head there are two bony prominences we call the mastoids, they are located just medial to your earlobes, press the bit of muscle and tendon underneath those two bumbs and breathe deeply.
These acupressure exercises can relieve some of the sinus symptoms for 20-30 seconds but sometimes they will help to unlock the sinuses allowing your to breathe freer. Enjoy!