Thanks for asking the query,
There can be chance of some broken root piece left in the socket due to which you are experiencing pain and swelling.
I would suggest you to visit the concerned Dentist
and get the checkup done, take an x-ray to see any left over tooth particle, if present it can be surgically removed.
Take complete course of antibiotics and analgesics.
Take lukewarm saline gargles and antiseptic mouthwash gargles.
Apply ice packs externally over the area.
Maintain a good oral hygiene
Hope this helps out.