Hi and welcome to HCM! Thanks for posting your query here. The most common cause of sore throat is streptococcus group of bacteria. It is commonly called as strep throat. Sore throat is the infection and inflammation of the posterior pharyngeal wall and its associated structures like tonsils. If the tonsils are infected it is called as tonsillitis. This will cause difficulty in swallowing of food. The first line of treatment will be pencillin shot. As you have already started the antibiotic Clamentin 625mg it is not advisable to stop in view of drug resistance. Clalmentin should be taken twice a day for 5 days. The infected phlegm-thick and green-is because of the infection spread to the upper respiratory tract. Clamentin is a broad spectrum antibiotic which will cover both gram positive and gram negative bacteria. Along with the antibiotic please add a decongestant combination like Sinarest- one tablet thrice a day untill the symptoms stop or a simple levocitrizine and paracetamol can be used instead. Salt water gargling will help in soothing the throat. If the symptoms wont subside in the next 2 days please consult your ENT doc for further management. Hope this is helpful to you. Regards