I just repotted my mom's fortune plant.. and it was a disaster..sopping wet soil...half the trunk was rotted. I ended up removing the rotten side--which was about half the trunk - dead half had no roots. The other half still has a lot of healthy roots to it. I was a bit confused with the soil..I made my own guided by google research 😅. I mixed coco coir, indoor potting soil by fafard, worm castings, orchid bark for 1 part, with 1 part perlite, and 1 part peat moss. Is this good soil? Will plant still recover? What else can I do?

This is a picture of how much of trunk left ☹️

wow
what does the whole plant look like?

The trunk is like that all the way to the roots. That half has a lot of healthy roots. The top looks like this (see photo). Should I have that gap on the trunk under the soil?

I have almost no experience with those. But I would discard all the roots, take the healthy top and root that.
A stiff breeze looks like it will snap