Left upper eyelid is heavy n sore. Started with twitching n now is paining. Have mild sore throat as well. Are they related? What's the actual reason?

See a doctor. When you start having pain in the eye with no apparent reason you most likely developing conjunctivitis and you need to have a Rx for special eye drops or eye ointment eye is a very special organ only drops and ointment are made for the eyes are allowed to be used they do required prescription it could be as a result of other infection in your body your doctor will evaluate and treat good luck.
?INFECTION. Could be.you may be starting a sinus/upper respiratory infection.probably more symptoms may develop and you need to see a dr.