Great job OP! 15 lbs is nothing to sneeze at. Agree w/ pp. download a calorie counting app (I like Lose It!, free version is fine), track everything you eat and see where you can cut. The older you get, the less calories you can consume, but I suspect there’s a slice of bread that could be cut.
But do this after the holiday. They are hard enough. Good luck, I’m right behind you.