Hi,
Noted your history about having had 
Hysterectomy 5 days ago but developed coughing, blocked ear on left side and so on.
The cause of the symptoms may be due to one of the following reasons:
Viral infection you might have got.
This causes the 
nausea.
Also causes 
rhinitis with congestion of the throat and infection goes through Eustachian tube to the middle ear with effusion causing blockage.
Coughing is due to the same cause.
You also have been feeling 
cold and hot.
I would advise you the following:
Since you have just undergone Hysterectomy such symptoms mayy cause early or late complications like 
hernia or so.
Hence it is important to have proper clinical evaluation and proper management with antitussive, decongestant, Nasal drops and so on along with antibiotic if required and anti-inflammatory medicines.
Hope I have answered your query. Let me know if I can assist you further.
Regards,
Dr. T. Chandrakant, ENT and General Surgeon