My boyfriend is an Army officer, and he's technically "overweight," per their standards, but he has a low body fat percentage. "Fat" is the last thing you'd think of when looking at him, but he's quite muscular. He gets taped all the time.
Just wondering, did you fail the PT because of being over the weight/height limit or was it because you weren't fit enough to pass the PT test (pushups, run time, etc)? I guess I don't really know how that works, but if your promotion is depending on just passing the PT test, it shouldn't take too long to get in shape. Probably less time than to lose weight.
I personally don't think that the military should adjust their fitness standards to accomodate for Americans becoming more overweight. It's a physical job, and the physical standards are necessary.
Welcome to 3FC, I'm sure you'll enjoy it here. Congrats on the 17lbs you've already lost, and good luck losing the rest of it