Same advice I gave last time - shapewear, and a sensible diet to follow longer term. I think I remember you mentioning you're already lifting, which is excellent for tightening things up, but diet is where the real, long term change will happen.
You don't need to diet severely or strictly, but you DO need to diet consistently. Pick a calorie level or plan and stick with it. The less severe, the better. Yo-yoing is a terrible trap to fall into, where you vacillate between starving yourself for a period of days or weeks and then throwing up your hands in exhaustion and hunger and falling off the wagon completely. Some of us on this board have very literally dieted ourselves fat - we began that cycle at a healthy weight like you, then went up and down, adding a few bad habits or a few additional pounds each new diet/rebound cycle, until our bodies were exhausted and flabby and our ability to discern our natural hunger cues and eat without extremes was all but obliterated. And that's a normal case, not a more extreme one, where lifelong disordered eating, hormonal damage, and secondary physiological conditions related to the diet issues popped up however many years down the line.
Pick a sensible plan, stick with it. Eat slightly less, focus on whole foods, control for a certain macro or ration, whatever. But pick something simple and stick with it. You likely won't see major results before your prom, which I reckon isn't far out now. But in time for summer, or next school year? The differences will be dramatic if you pick a plan and stick with it, along with what you're already doing