What am I doing wrong?

I am a size 14 in pants and 12 in dress, 26 yr old woman. I work out all the time with weights & aerobics and switch off with cardio every other day. I just want to get down to a size 10 (an 8 would be nice, maybe). I try to stay away from refined foods and eat whole wheat whenever possible. Also, I try to always eat in moderation and not to "splurge". I'm not losing weight and concerned that my muscle gain is just adding extra weight in addition to my adipose tissue. Some thoughtful advice would be appreciated!