I know it is VERY frustrating. It really is a good example of why we should rely less on the scale though.
I know about 5 years ago, I lost about 25 lbs. and only went down 1 clothing size. Talked about annoyed! I was expecting miracles! But I was just losing pounds, not inches. So I started working out, and low and behold 5 lbs. later I lost TWO more sizes (in only FIVE pounds!). I know a lot of people avoid exercise like the plague (I used to be one of them) but as they say - the proof is in the puddin'!
Don't give up. At least you know that you can do it! Just stick to it!
Like twiceblessed mentioned, exercise will help tone you up which, in turn, will loosen those clothes (that doesn't sound right, but I hope you know what I mean!). Also, some of that may be water weight, which I don't think you notice as much. I know in the past, I used to gain weight the first week or two of a diet. Without fail, I'd be up 2-3 lbs and then it would start coming off. Everybody's body just works differently.
Regardless, I hope that you stick with it. Even if you're not seeing the results just yet, that's 15 less pounds that you're carrying around on your body. That's a great accomplishment! If you don't believe me, go to the food store and lug a 15 lb turkey around the store for a while.
Don't worry if you can't tell in your clothes just yet...your just loseing in equal amounts off your body and thats a great way to lose, its a safe way.
Just keep on doing what your doing you may not tell much diffrence in your clothes until you have lost up to 50 lbs depending on how much you need to lose.
KEEP YOUR CHIN UP IT WON'T BE LONG NOW BEFORE YOU CAN SEE AND TELL THE DIFFERENCE.
DON'T LET YOUR BODY WIN THE WAR...YOU CAN DO IT.
don't give -up
Keep on truckin girl.