The odds favor the problem as being over-watering, or a soil too water-retentive.

Plants do best when the entire soil mass is barely damp. They do poorly when a fraction of the soil remains saturated between waterings, and the larger the volume that remains saturated, the worse they do. AIR, is as important in the root zone as water. The process of water/nutrient uptake is energy driven, and requires plenty of oxygen to be performed with efficiency. Your soil choice and watering habits are tightly linked and very important to how well your plants CAN do, and how easy or difficult it is for you to bring along healthy plants.

That's enough for now - I won't bombard you with tons of information, but I'll leave you with the thought that knowledge is the fastest way to a green thumb. I'll leave you a link that covers most of the basics. If you decide you want more details or to learn more about growing, let me know and I'll furnish another link or two that should provide a considerable degree of illumination.

Al

Here is a link that might be useful: Click me, and I'll take you to some basics ....

I vote over-watering as well. Good luck, I know how important this plant must be to you.

I will try waiting a little longer in between watering. The air in my apartment is pretty dry though and the soil at the top of the plant gets dry enough to pull away from the sides of the pot within 24 hours or so of watering and it worries me.

Also, should I trim off all of the leaves that have started to turn yellow? One of them fell off in my hand today and the stem was weird and mushy.

Thanks for all the help everyone!