Camera stills pans upward
Camera still pans upward. Ive reset defaults.
Started a new game unistalled a new game. This needs fixing its been years now
Your right stick is most likely broken. What other games do you play and does this happen in those games as well?
Probably an issue with your controller's right analogue stick (the potentiometer is probably starting to get bad). Try swapping the stick mapping and see if the problem moves over to Nate walking backwards or forwards (depending on if you play inverted or not) by himself without any stick input.... or try another controller (preferably a newer/less used one).
Also, when you uninstalled the game did you also remove all of your U4 save files and the profile file? If not, make backups and then delete them, and then try a new install.