I find too many people drop their calories too low to chase after the weight loss. did you redo your rdi with the halfway mark?? at this point you will be curbing your fats a little more. Make sure you are getting enough protein. Getting more exercise will help you burn off fat while your body is adjusting to the new weight loss. the more agressive the exercise the more protein the body needs and can handle. the body does fight back as it likes things nice and cushy.
I dropped my calories too low and stressed my body. It cost me, so I am just saying avoid that tactic and try and be patient.