I Want This Furuncle Cure Permanently

Developed furuncle about 20 days ago on left knee. Initially I have taken Zanocin 200 mg for 5 days twice and there was improvement. After 5 days my doctor prescribed Amoxyllin Potassium based drug. But after taking that drug for 1.5 day the furuncle reappeared with much wide area i.e. grown up to 6 cm in diameter with severe pain. So I stopped the Amoxyllin based drug and continued Zanocin for 3 times daily for 7 days. Now it is showing much improvement, the pain is extremely low now. But there are some wound like areas are there about 0.5 cm wide, 1-1.5 cm long. Very low clear fluid is draining very few times. Zanocin is being continued. Bath is taken with dettol and furuncle area is being washed with dettol after the bath and before sleep. Please advice to have this furuncle cure permanently, sooner, and avoid it to grow up again.