I have fair skin color on certain parts of body. Is there any cream that can make my whole body a fair color?

I have fair colour on breast and thighs. But my stomach and backside body parts starting from neck to back knee it's black. I want to get my fair colour to my full body. My marriage is fixed on Dec. Plz help me. Parents doesn't want me to see dermatologist for tis. They belive its a simple problem. Suggest me any cream or lotion so that I get fair colour before my marriage.