Welcome in H.C.M.
I have gone through your query regarding frequent difficulty in swallowing, blocked nose, pressure on right side of face and mucous in throat.
Since your sinus
X-Ray and endoscopy
under camera had already been done and no abnormality is detected. this indicates that basically you are suffering from allergic disorder, your allergy
in nose from time to time give rise to oedema which results in nasal obstruction
and you feels pressure on right side of face.
This allergic inflammation in throat give rise to mucous in throat also. Therefore if any investigation is if carried out may be reported normal because this depends on attack of allergy.
I hope your query is answered.