Trigeminal neuralgia (TN) rarely occurs with sinus
itis but it has been described. The persistent congestion
and your severe headache suggest that, despite the "clear" sinus
x-rays you may have sinus
itis or an infection of the sinus
that has extended beyond the sinus
That you are still ill suggests a possible infectious complication. You would do well to consult with an ENT specialist and have a CT scan of your sinus
es and the adjacent areas.