Pain in right ear since 5 days. No discharge

Pain in right ear since 5 days. No discharge. Presence of fullness of ear. No hearing impairment. Left ear not involved. What would be the diagnosis and tt? There is no current episode of sinusitis or sore throat. Could it be just eustachian tube obstruction or otitis media? No fever or signs of inflammation. Haven’t examined the ear with otoscope coz I don’t have it.