You don't tell us you height.If you are 1.65-1.70 your weight is ok...if you are shorter you maybe have to loose weight...
So your ok!! If you just want to lose some weight for you try to eat healthy and domt eat sweets bread etc !! ;)
You don't want to throw away your muscles. Muscles are what keep you from getting fat. Maybe you just want to tone them. Instead of dancing being your only exercise, try doing some other things as well, such as exercises using your body weight, like yoga or tai chi.