hello there , According to your clinical history i suspect you have suffering from acute pharyngitis . It is inflammation of the throat mucous membrane caused by bacterial or sometimes viral infections seen post flu infection . It presents with symptoms of sore throat, pain and difficulty in swallowing ,fever , cold , headche as you have mentioned. i would suggest you to start with antibiotic augmentin 625mg along with analgesics with antipyretics for 5 to 7 days. maintain good oral hygiene, use lukewarm saline water or antiseptic mouthwash like chlorhexidine or betaine for regular oral rinsing. i hope this helps , take care.