My complexion seems to to be getting darker like nearly every month and I hardly go out so the sun is not a factor, how do I get it lighter?

Fair Skin. I am not sure you have a medical problem or condition. But, given that you are seeing change you may want to confirm this with a trusted family doctor or dermatologist. One cannot in any way change their genes and skin is a good example of this. Having a darker complexion is in no way a disease. But, the wanting something different than how you were created can be a significant mental problem.