Hi,thanks for your question
Most probably you are having pharyngitis
(infection of throat) Difficulty in swallowing,sore throat
,headache and phlegm with blood in throat are all symptoms of sever pharyngitis.
I would suggest you to get your throat examined by an ENT surgeon ,who may also take swab from your throat to determine the type of infection your having and accordingly he may prescribe you treatment.
You may may need a course of antibiotic,antihistiminics and decongestant.
Hope this answers your question