Welcome to 3FC!
Congratulations on the progress you've made! That's amazing
If you've hit a plateau that means you've been weighing the same for the last month or two. If it's a true plateau it could be a couple of things.
First. Be honest with yourself. Are you tracking as diligently? Exercising the same as you were in the beginning? Or have you slacked off a bit? If you've slacked off a bit... there's the problem. It can be easily fixed.
If however, you're honestly still working just as hard, then it's simply time for a change. Play around with your calorie intake. Up it a little. Then lower it a little. See if that works. Try a new activity or exercise to keep your body moving differently. Try new foods or a new recipe. A little change can sometimes shake the body up and the scale around.
Best of wishes!