I received a beautiful Calathea insignis plant as a gift. It's been only two weeks but the leaves are curling up and some dried out completely. I keep the pot on my work table and the windows of the room are almost always shut due to the dust in the air. So, my room gets heated up in the daytimes and warm at nights. So, I occasionally use my air conditioner to keep the temperature at balance. I understood that this plant needs humidity. I live in a coastal area. So, the air is naturally humid. However, I couldn't place my plant anywhere except my room.

Image 1: when I first received the plant.

Image 2: After two weeks

Image 3: after two weeks.

Please share your advices and suggestions. I can't see my plant suffer anymore.