If you are feeling better, or if the size/ pain of the swelling has reduced in the last two days- basically if you feel there has been some improvement, then you can continue with Staphysagria. It is said to be a good medicine for styes, and will help in most cases.
However, there are at least 30 medicines in Homeopathy that can cure styes, and the best medicine for you is the one that suits you 100%.
If your swelling is the same, or increasing, or if sune other problem develops, then it means Staph200 is not helping you.
Other things to do:
Hot fomentation: apply dry warm cloth on eye. Do this for 2 mins 4-5 times a day
Don't touch the area too often
Wash your hands with soap and water regularly
Next Steps
If stye remains even after 5-7 days, take online consultation through Practo for a medicine that's individually suited to you.