Thanks for asking the query,
According to your history i suspect that a temporary filling with a medicated piece of cotton was given to you which came out. You probably have developed pus in the tooth, foul smell is due to the food lodgement and pus accumulation.
Such an abscessed tooth is indicated for Root canal treatment
to save it permanently. I would suggest you to visit the Dentist
and get the checkup done, take an x-ray of the tooth.
Go for symptomatic treatment of complete mouth scaling and polishing.
Take complete course of antibiotics and analgesics.
Maintain a good oral hygiene
, use antiseptic mouthrinses twice daily.
Hope this helps out.