I weigh 127-129 (in the mornings)

and I would like to get down to 120 and "tone"...I have really started being consistent with the gym (4-5) times per week...walking a minimum of 45 minutes on the treadmill for 4.0-4.4 miles per hour and an incline of up to 5. After walking, I always do some ab exercises and sometimes do the "women's room" which is basically set up like Curves. I am overall happy with my body except for my butt and thighs..ugh!!..I get so frustrated because nothing I do seems to really help..I have heard that only 20% of it is exercise and 80% is the way you eat..and I don't really eat that well...are there any suggestions as to what else may help me more that what I am doing currently? I even have a little cellulite that I CAN"T get rid of and I am only 24! Is there a different way I should be walking or should I jog?? any suggestions would be helpful..I hate my lower body!! (sorry this is so long)