As Brat said, fitness is the way to go.
Now it's time to develop yourself an eating plan that you can live with - it will very likely be more food than you are used to eating, there may even be some weight gains initially but not to worry...they are usually just water and muscle. But if you've been undereating, you will have to reset your metabolism to burn fat.
For fat loss, I personally prefer a ketogenic diet with a gradual transition once it's gone to a "normal" diet by slowly reducing fat intake and increasing
carbohydrate intake. Sadly, it appears I've got one of those bodies that will have to live on one forever.
After you make your nutrition plan you need a resistance training plan and a cardio plan.
I'd suggest a full body lifting workout 3x a week and cardio 2x a week. If you aren't getting the results you want...you just add another day of cardio.
I'm working with a few ladies here in my town (no I'm not a qualified trainer, just learned this stuff the hard way and am the closest thing we have to one here). Some on 5x5, some on HST, all on
ketogenic diets (to get in that bikini by spring). All are getting astounding results. From your description, you aren't far from that spring bikini.
I hope this is somewhat helpful information to you. If you need more specifics, just ask. These folks helped me a great deal as I was learning, they will help you too. I too, will do my best to offer what I can.