Monstera plants need bright indirect light. They should be watered when the top 2” of soil is dry. The pot should have drainage holes in it. The soil should be able to drain within a minute or two after watering. Don’t let it sit in water. If the weather is mild and sunny I put mine on the patio just out of direct sunlight. If you haven’t fertilized yet think about doing that also. Hope you can save your plant!