HI.Thanks for an elucidate history.
As per your chronological history, it looks that your husband is suffering from Viral fever/ flu giving all the symptoms he has. He must caught this at the swimming pool.
So he got the blocked ears first but you all thought it was due to swimming. So also got the other symptoms of head cold
, fever, sweating,; diarrhea
can again due to viral tummy as is nausea
The treatment plan should be :
Bed-rest, decongestant nasal drops followed by steam inhalations. Domperidone
and such supportive and symptomatic treatment .
Antibiotics are added only if thought to be due to bacterial infection.
Sorry to know that this happened during the most crucial stage of life of honeymoon .