How to break this weight loss plateau??

Hi, I'm about 160lbs and trying to lose about 30lbs. I started a week or so ago and lost 5lbs, but this week I've lost nothing! I know I'm probably being impatient, but it's so frustrating when I can't see what I'm doing wrong. I eat about 1,100 calories a day, mostly protein and low carbs plus about 30 minutes of exercise. Does anyone have any tips for helping my weight loss? Or am I just being impatient? Thanks!