Q.Dying Cactus Help!
My cactus has been having issues for about a month now. I tried to replant it a month ago, but it fell during the process and the top split open a little and the cactus bent in the middle. I gave it support and hoped that the top would heal. Unfortunately, the top turned black and got mushy. I cut it down and put some cinnamon on it, but the top again got black and grew mold. I tried the same method, but just cut a little further down. It still didn’t work, and yesterday it folded over on itself. I tried today to cut it down past where it had gotten mushy in the middle without my knowledge, but the bottom does not look very healthy. There was a middle piece that I was able to cut out that seems mostly healthy. I dusted the ends with cinnamon and was wondering if I can maybe replant it. Do I need to let it dry out or should I replant immediately? And is there anything that I can do about the bottom part? I’ve attached some photos below.

I'm sorry your plant has suffered this damage.
Yes, it is possible to propagate cuttings, the likely hood of success with a section, unfortunately is not good.
With that said, with your determination is certainly is worth a try.
I located this link with information on the best process.
Good luck.
https://extension.arizona.edu/sites/extension.arizona.edu/files/pubs/az1483.pdf