I'll try to help you
@Abby6996, but diagnosing problems such as this is difficult.
As long as you have well-draining soil and good drainage holes in the pot, in my opinion, you simply can't overwater. Dismiss "root rot" from your mind. It is a much overused term. Also, when you water, do so copiously, until lots of water runs out of those drainage holes.
Do not fertilize. So many people think that fertilizer solves all ills and that is farthest from the truth. Wait until you see nice, maturing growth to fertilize. Fertilizer now will only further stress your plant.
I don't really know how much light you plant is getting, but keep in mind that this is a tree and in nature, they get full sun. That's what my fiddle leaf ficus gets. Keep in mind that your plant almost surely was grown in a greenhouse/shadehouse, and thus probably got bright light all day long. These trees adapt to lower light levels, but still, they need really bright light to do well. I have a feeling that your plant isn't getting enough light.
There are other issues, such as lack of humidity in our homes and lack of air movement, but you need to deal with the basic problem(s) first.
Good luck.
