So, I had a mod installed that included a seating area, basically a chair, and I saved the game there. I uninstalled the mod, unaware that I had been sitting on it before. I started up the game, and I was already standing up. I equipped my weapon, but I saw that, when I unsheathed it, it wasn't there. I zoomed out and saw that my character was in a pose that was standing straight up with arms down at the sides but not touching the body. (If you were to use 'setrace' and keep the console open, your character would be in that pose) So I tried loading an earlier save with that same mod installed, but I had to download a mod that I had before because it was in a cell used by that mod. But, to no avail. My character was still in that pose. If anyone could help, I would greatly appreciate it.

EDIT: I have found that no NPC except for non-dialogue creatures (such as wildlife, like bears and wolves) have any animation. They can still speak, but they don't move. I want to get this fixed as soon as possible.

It sounds like you added or removed an animation-based mod (probably the chair mod), and you need to run FNIS now to re-build your animations and fix it.