Hello rookieplant guy
The other rightmost stem still looks it has some infection, so cut further down a bit more, you have to see how far along that rotting is running. Then once cut off apply some light cinnamon, and let it heal. Give it time.
Also you said your media is still damp, so leave it alone. Check back after a couple of days, use bamboo skewers to check if media below is still staying too wet. Delay watering a few more days again if it still stays too damp wet.
At times either the plant will make new shoots below the cut off point, or it may just decide to do a new basal shoot. So just be patient and wait. Run your ceiling fans a few minutes or open up a window weather permitting to increase better airflow all over your plant especially when you water that day. Root level always takes time, and if soil is too heavy and dense even more.
You can also try to mix into the soil some perlite or pumice. I am not asking you to repot, just mix in some of those gritty material to help the root area find better air flow. Roots also need to breathe properly. That is why containers with drain holes, media that is well draining, good discipline in watering, no fertilizers when plant is in visible stress. Those things you have to keep in mind for your plant's better growth later on. Again, good luck!
