Here's how I'd do it. Try to isolate which light(s) are causing the problem. If you can identify your primary light source, turn all the other ones off (for now). Start with adjusting the intensity of the primary light until it you get it the way you want it. (you might also try using the "texture shaded" document display to give you a better idea prior to rendering). Then begin to bring in more light to "color" the rest of your image.