I really don't think your diet can affect your skin that much.. obviously if it is extremely chocolate,oil,fat driven and you cut those down, it'll improve, but I eat a relatively healthy diet (loads of fruit and veg, nuts, water) as well as the usual balanced stuff and my skin is still crap. If it's really bad could you perhaps progress to drugs rather than a cream. Otherwise, you might just have to ride it out until you are of the age when skin seems to magically behave.