Your symptoms described typically point towards a developing stye
Please dip a clean cotton swab or cotton handkerchief in warm (not very hot) water and do hot compresses over the painful region of the eyelid
Do this for atleast 5 to 10 minutes in every 2 hours, by tomorrow or day after tomorrow 2 things can happen
1- either the swelling subsides (then continue the compresses for another couple of days)
2- a small pus point may form in which case don't burst it it will mostly rupture on its own; if it doesn't and swelling becomes more painful then please visit ophthalmologist in opd who will remove the collected pus under hygienic precautions
Next Steps
Do post your symptoms and recovery/any worsening in another 1 or 2 days to get updates on further management
Health Tips
Don't touch the painful part of eye with bare hands
maintain strict hand hygiene