Help Needed!!

Hello all, I'm going to lay it all out on the line. I've changed the way I eat, started working out again and still stationary at the same weight and inches.. I am 28 years old, 5'2'' and weight 128. I want to lose about 10-15lbs. I drink nothing but water and eat usually about 1200 to 1000 per day. I know that's low but I don't have a large appetite. Here is what my average day looks like.

8am I eat yogurt or a piece of fruit.. Banana, Grapefruit or an Advocare Shake

Around 10 I eat a handful of mixed unsalted nuts. Cashews and Almonds.

11:30 or Noon I eat a small lunch. Chicken Caesar Salad or Tuna in a tortilla

head to the gym around 4/5pm and workout for about an hour. Cardio, Spin Class, Insanity, etc..

Dinner is around 6 or 6:30 and it's grilled chicken with veggies..

I have not lost any weight. WHAT AM I DOING WRONG??? Please help. This is going on almost a month and I haven't lost a pound.