Swelling and irritation continue a month after conjunctivitis. Why?

Hello doctor,

I am a 29 year old woman. I have been diagnosed with conjunctivitis a month ago. After initial medication, the pain reduced a little, but swelling still remains. I have a feeling of irritation (like something pricking inside the eye). Hence, I visited a hospital again. My doctor gave Tobramycin fluorometholone for a week. But the swelling and irritation continued. On the next consultation, the doctor referred me to another ophthalmologist who is specialized in eye infections as she doubted whether a biopsy is needed. After investigation, the second doctor said that a conjunctival mass is seen above the eyeball, under the eyelid. She suggested Tobramycin dexamethasone ophthalmic solution for three weeks. I had a ptosis correction done in the same eye four years back. Occasional swelling of the eyelid occurs due to allergy (which was frequent before the surgery also). The eye is again drooping as a result of these issues. Only the left eye has these problems. Right eye has no issue. Can this be a case of melanoma which needs immediate attention? My next hospital visit is three weeks later. Is it okay if I wait till then?