Q.Why is my mandevilla dying?
It was bought a few weeks ago. It was doing great. It was outside on the porch. It got sheetrock dust on it. I washed it off best I could but it’s not helping. What do I do? Oh, I did bring it in, but that didn’t help . I don’t want to lose my plant!!

Your plant may need to be watered more often. A container plant outdoors will need daily water, even twice a day during hot weather.
This article will help you.
https://www.gardeningknowhow.com/ornamental/vines/mandevilla/mandevilla-plant.htm