Muffin Top

I'm going through a thing....I'm kind of freaking out.....I have......a muffin top. For the first time in my life (other than when I was pregnant) I am feeling very jiggly and out of shape. It's frustrating really, because by all standards, I'm not overweight. I even looked at the charts to make sure and for my height and bone structure I'm really very normal. Don't get me wrong; I'm glad that I look like a 41 year old--I have curves and I've learned to appreciate them. But there's this doughy part around the middle, just above my jeans (and a little bit tucked into my jeans) that's got me stressed out. I'm embarrassed to wear snug-fitting sweaters & t-shirts and I have a strong urge to constantly fold my arms in front of my stomach when I'm sitting down.
So how do I get rid of this blob around my middle without losing the rest of it? I don't want to have jugular-slicing clavicles or bruise-inducing hip bones...I just want the tone back while keeping the curves above & below. What's the best way to do this? Suggestions? Routines? I'm all ears....