Hi thanks for your question.
This lump is most probably an enlarged lymph
node(normally present in all individuals and get enlarge if there is infection in its vicinity) due to your throat or ear infection
.This lymph node is on some artery
most probably external cartoid artery that is why your feeling pulsation.With the treatment of your throat or ear infection the lymph will regress.If it doesn't regress after treatment and giving you trouble,consult an ENTsurgeon and get it removed.
Hope this answers your question.