Get checked ur tear film.  Heaviness can be because of getting tired while reading for long with less blinking. Itching can be due to dry eye.  If ur vision is good and u feel like no glass correction needed.  ...go for artificial tear drops.  4 times a day.  If the syptoms persist consult nearest ophthalmologist.

Need to know power of your near vision glasses

For your height your weight seems to be quite high. Have you checked recently for diabetes or hypertension? coming to the pain in eye muscle is there associated blurring or double vision? Do you eat non vegetarian food as sometimes worms can lodge in the eye muscles? If there is swelling of the muscle you may need a scan to see if there are any.

Could be long standing allergy which is being exacerbated with near work, consult an ophthalmologist for better evaluation

This is most probably due to strain due to refractive error. At your age, you have to use reading glasses for Presbyopia. Itching might be due to dryness or allergic reaction. Send a photo for better evaluation.