Probably roots plugged the drainage holes and more and more water kept accumulating in the pot so the roots started to suffocate and the top started yellowing.
Many people do this thing. When they see that their plant starts to yellow they think that soil is too dry and keep watering more and more often.
Even tho Areca likes to have "wet feet" what you did to her was OTT.
Take it outta the pot and check the roots. If you see any white ones there's still some hope. Shake the soil off the roots, cut off any brown stuff, spray it with a systemic fungicide, plant your plant into a new pot with fresh medium, place it in a warm shady spot. Keep the soil warm. If you can put the pot on an electric pad. Water it moderately (dissolve some fungicide in water first).
And if you manage to save your Areca, remember to check your plant every so often.
Good luck