hello there ,
After reading your history i suspect you have developed severe soreness in your throat which may be caused due to allergy
of the filling materials used during treatment or trauma from broken filling pieces.
may lead to pain and discomfort , difficulty in swallowing, redness
and sometimes swelling of the throat mucosa.
NO it is not possible to have pocket formation in throat ,dont worry symptomatic treatment will solve your problem.
Use lukewarm saline water or antiseptic mouthwash like chlorhexidine
for mouth gargling regularly for 3 to 5 days till the symptoms subside .
eat soft food , avoid hot and spicy foods and carbonated drinks .
In case of severity you can start with antibiotic course of augmentin
with analgesics for 3 to 5 days.
i hope this helps ,