Please I Suffer From Very Bad Skin Pigmentation, I'm Light

Please I suffer from very bad skin pigmentation, I'm light in some areas and very dark in some (eg my inner thighs and underarms and neck area)! I also just had 2 kids and after that I developed very deep and terrible stretchmarks! What can I do to have fair and glowing skin and get rid of these stretchmarks! I just want to add that I'm a black woman! Please advise