Painful swelling of the lid of short duration of 2 days is more indicative of a hordeolum of the lid ( external type is commonly called as stye). This requires a course of oral antibiotics, oral analgesics like paracetamol 500mg twicw a day, hot fomentation to give relief from pain. With this treatment it subsides within 3-4 days.
If there is no significant swelling of the lid margin and only the inner end looks swollen then the itching could be due to allergic conjunctivitis. This can be treated with a short course of steroid eye drops and mast cell stabilizer eye drops.
A visit to your ophthalmologist will confirm this. In the meanwhile please continue with hot compresses and oral analgesics.
I hope your doubts are clarified.
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These answers are for information purpose only and cannot be substituted for a check-up and visit to an ophthalmologist.