I think your goal of 120 is really low for someone who is 5'7". Looking at height alone I'd say you are in a good range and even if you wanted to get down to 135 (which I think is very ideal for your height) the last ten pounds from what I hear are ALWAYS the hardest to lose. I do agree to up those calories a bit and I'd also say increase your workouts- even if it's 15 minutes a day.
But at your weight your BMI is 22.9- which is very good
