Without having any more information than what you provide, I can only say that I suspect you are like the rest of us. We want to see immediate results. Our bodies just don't work like that. How long have you been trying to change things in your lifestyle?
For me, it took me years to put on my weight, over a long period of time. So realistically, how can I expect to take it off in a matter of weeks?
Your body has to make lots of adjustments for whatever you're doing that is new - eating better, exercising, both, etc. Give it time.
Hang in there!!! I KNOW how frustrating it can be. If you remember anything, remember this:
It's NOT about dieting; it's about changing to a healthy lifestyle, a lifestyle that you can maintain forever, or the weight will come right back. So take small steps, and just keep with it. It's about progress, not perfection!!!