Hi. have a mild sore throat, glands on side of neck up, feels like post nasal drip and slight nausea and very tired particularly in the mornings plus slight headache.

Cannot diagnose...: It is hard to mention with the limited amount of information, but it is obvious something is happening. All what you mentioned should be absent from a healthy person. Since you are in South Africa, I am not sure how your medical system works but it is best to consult a physician, then get a referral to an appropriate specialist, if needed. If you cannot see a doctor, try to find "Tele-medicine".

Symptoms: You would need to be assessed and possibly be tested for COVID or other issues to know your diagnosis. Suspicion for COVID 19 is higher with at least 2 of these sx’s: temp of at least 99.6, Cough, Shortness of breath, Chills, Shivering, Muscle pain, Headache, Sore throat or new loss of taste or smell.