I have heard that many people using Skinlite or Melacare have the same problem: The product works fine when inconstant use, but the skin becomes blemished once usage stops.
I wonder if this is a ploy or trick by the manufacturers!
Anyway, there's two things you need to do:
1. Stop using that stuff! It is doing harm to your skin, not only the pigmentation, but it will make your skin dry and coarse, very unappealing!
2. Once you stop using it, look for more traditional and "natural" ingredients to keep your skin looking fair and clean.
I hear lemon juice and egg white can do wonders, and will mean you are not using unsafe chemicals - but it may be worth researching further skin care methods or even asking a new question to see if anyone else has suggestions for after-care and lightening in a more natural way!