Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concern.
As per your complain and presentation of symptoms the orange seed does not seems to have been present in the throat or base of the tongue rather while there is a possibility that it has traumatized the mucosa of the base of tongue and the throat while passing through..
Due to inflamed and injured mucosa there is a pain appearing on swallowing..
Nothing to worry as it will get resolved soon.
Take soft and col diet.
Avoid hot and spicy food to prevent further irritation.
Drink plenty of cool water.
Do warm saline gargles.
You can also take anti-inflammatory painkiller like
Ibuprofen for reducing inflammation and pain..
If you do not find improvement in a week, consult an Otolaryngologist and get evaluated.
Hope this information helps..
Thanks and regards.
Dr.Honey Nandwani Arora.