Is Homeopathy always a slow-acting medicine that I will have to take for the rest of my life? 

This is not true!

Homeopathy can give quick effective results within 5 to 10 minutes in severe cases of gallstones, and renal and abdominal colic. It can bring down your temperature in just 10 minutes in case of high fever and works effectively for chronic conditions such as arthritis, skin allergies, or asthma which have affected the patient for 15 or 20 years. The remedy will need to be given for six months to a year to treat the problem effectively.