How To Treat Bruise Caused Due To Rashes On Body And Face?

Hi.i had very bad time with skin recently..bcoz of overdose i actually had sideeffects as very bad dry skin and it touched nearly all parts of my skins..rash seems to be going slowly but it is leaving bruises on my legs,arms and belly and now on my face around eyes and on the top side of nose which is close to eye is getting very dark...i dont understand why is that as i am using a good moisturising cream as my GP suggested it..but they are not going..i am really worried about it as my skin colour is fair and it looks very odd..i also avoid using any make up so i can t even hide them...could you please suggest a good and effective way to get rid those black patches and bruises on my skin..Thankyou