This part, right?
View attachment 357363
The easiest thing will be to go to
car-part.com and look for 2wd T100s that don't have smashed front ends. Try searching for "steering column shaft" or "steering rack" and see what you can find. You're really just looking for nearby yards that have 2wd T100s. You'll end up having to call and ask if the part is good. I just went through this looking for a discontinued crossmember on my 4wd T100. Lots of these yards will ship parts to you at a reasonable cost.
Or you can go to a You-Pull-It type scrapyard and compare your shaft to 1st and 2nd Gen 4Runners, Tacomas, and Pickups. You may find that one will fit with little to no modification. Parts from these yards are typically very cheap, so buy and try is an option. T100s share a lot of steering/suspension DNA with the old Toyota Pickups.
I'm guessing it's the U-joint on the end that is bad. Some of those joints are rebuildable. Here's a relevant
Tacoma World Thread that covers the process on a 2nd gen. The challenge will be finding a joint that fits. You'll probably have to measure the old one.
Let's say you can't find a replacement part, and you can't retrofit one from a Tacoma, 4Runner, or Pickup. Let's say you also can't find a replacement U-joint to rebuild the shaft. All is still not lost, but you're in fabrication space now. Next option is to buy a similar shaft from another Toyota and shorten/lengthen it as necessary. Or you can try retrofitting a rebuildable U-joint from an ATV driveshaft or another Toyota on there. Not easy, but I think it's better than scrapping the truck.
Hope something in there helps.TLDR
4 Options: 1. Find scrapyard replacement
2. Retrofit replacement from 4Runner, Tacoma, Pickup, or other
3. Rebuild steering shaft with new U-joint
4. Modify/Fabricate a working steering shaft using existing parts