This has happened to me a few times in the past. My character will be sneaking around, being all sneak and such. Then I will get on a horse in Sneak mode, or fast travel in Sneak Mode, or Save and Reload while in Sneak mode, and I get a game breaking issue. I look like I am in Sneak Mode, but I am not. I do not pickpocket or get a Sneak Damage Bonus, but I am still crouching around. The worst part is that I cannot change out of this weird inbetween mode.
This is made even worse because I just cleaned out my save files, so my only save with this character is like this. Normally it would not be a big deal, I would only look silly, but this character is based around sneak. I have every perk in that tree and I can only kill effectively with the bonus. Any fixes?