Hi welcome to health care magic. According to history you are having viral sore throat infection .... It can lead muscle ache and stiffness as constitutional symptoms.... For that Drink lots of fluid.... If congestive symptoms felt like cough and runny nose take antihistaminic drug like diphenhydramine ..... Excess spicy and fried food avoided. Frequent sips of hot water help in relieving inflammation.... Salt water (hot water) gargles done two to three times..... One tsp ginger juice with honey useful in congestion relief.... For stiff muscles hot pad can be applied.... If sore throat increasing with cough then posterior pharynx swab taken. If still no improvement then your physical examination done by physician or Ent surgeon and accordingly investigated. Take care....