Seeking Remedies for Idiopathic Guttate Hypomelanosis (IGH)

Hi there I'm a female who just been diagnosed with idiopathic guttate hypomelanosis. And my skin Color is brown but some parts of me is like a fair colour, from head to toe very uneven and the browner parts of me the white spots show with freckles on my stomach. I realize that some treatments arnt successful in getting rid of the white spots and I'll accept that, but my goal is get a even skin tone all over, since my face is more white and from the neck down to my thighs are very much brown. Can you please help me with telling me something that what should I do in getting a even skin tone from head to toe? Besides applying sun screen....any type vitamin supplements? Or cream? Or Lotions? Or foods anything is good please help me as this has caused me depression...I just want my body to matched the tone of my face colour