hello and welcome,
the pain and difficulty you experience is due to the decayed tooth present.
the pain won't subside unless and until you are getting treatment for your decayed tooth by your dentist
.an x-ray is required to finalise the treatment as the decay is deep and involved pulp.
if there is radiolucency in periapical area,root canal treatment
if only coronal pulp is infected,pulpotomy
with formocresol or indirect pulp-capping with calcium-hydroxide or vitapex should be done.
if there is abscess
and curettage should be done.
take antibiotics complete course prescribed by your dentist to subside infection.
get your teeth cleaned by your dentist.