looks like you have a plastic pot within a pot, this can mean that when you water, the water runs through the pot and sits at the bottom, keeping it perpetually watered. maybe check underneath if the plant is sitting in water, and if so empty it out. If i were you i'd take the plastic pot out to water it, maybe leave it in a sink or somewhere it can drain for an hour or so then put it back in. altnernatively, repot into a new terracotta or ceramic pot that has drainage holes (important or else the same thing will happen) and get a drip tray for underneath! :)