If you have been using contact lenses previously, then the commonest cause of symptoms like yours is dryness of eyes. For this you need to use lubricating eye drops like systane, genteal, refresh liqigel etc (available over the counter). If still the symptoms persist after using the lubricating eye drops, then you need to consult an Ophthalmologist to check for any increase in pressure of the eye or any change of prescription of glasses if required.
A blocked nasolacrimal duct will present as excessive tearing in the eye. Also, there might be some discharge in the inner corner of the eye. Your symptoms do not seem like a blocked duct. In case one of the nerves is involved, there is usually restriction of movement of the eyeball in one of the directions.
Since your eye evaluation is normal, there can be a possibility of a stress headache or migraine. You have senstivity in the right side of head with uncomfortableness in right eye as well. So, the symptoms might be that of migraine, specially ocular migraine which might not present as frank headache. I would recommend you to consult a Neurologist for a detailed evlauation. In the meantime, continue using the lubricating eye drops to avoid any dryness.