why does dead skin keep building up and not shedding like normal?

[muddybrowneyes]

For the past year, following the use of two moisturizing products, my skin has continued to darken and be blotchy. I used two moisturizing products for two weeks on my skin. the 1st was African shea butter and the 2nd was Ambi even and clear moisturizer with SPF30 in it. I finally think I figured out what is going on. MY skin just keeps building up dead skin, but not shedding like its suppose to , even with manual exfoliation. It will temporarily lighten, and then the next day get darker. And I dont have time to constantly scrub my skin like that on a daily basis. It is time consuming. I know that your skin is suppose to be constantly shedding without us being aware of it. but I think that my skin has stopped doing so completely. I am in my early 20's , is this even possible ? Could this be a permanent reaction from using products that didn't agree with my skin, even if it was just for 2weeks over a year ago? I have literally gotten 5 shades darker since I first used the product. I look like a completely different person.