Stuck! No weight loss happening! Help

Hi,

I'm on lite n easy and eating between 1200 - 1400 calories each day, halfway between what lite n easy recommends, 1500 and my fitness pal recommends, 1200. I'm been on l'n'e for 2 and a half months and was losing weight steadily 1 kilo every week or every second week. A bit over two weeks ago i lost 2kg, then gained back 500grams, then lost 200grams and have now stayed at that weight for two weeks. I can't workout what i'm doing wrong, am i plateuing? Not eating enoug/too much? Not enough exercise?

I do 30mins treadmill in the morning, 30mins at night of 1 min walk, 1 min jog. I tend to eat back 100calories after the exercise at night. I also do 2sets of 3kg weights morning and night. Should I bump upexerciser or weights?

My stats are 157cm, female, 68kg

Any help would be very welcome!
Thanks!