Everytime I go through a door the camera spins, which honestly makes me feel a little sick. is there a fix for this, because it's making me not want to play the game?

It's a known issue, that usually only happens with controllers. Ad hoc I don't know a solution, but the spinning shouldn't appear when you use the keyboard and mouse and neither when entering with a sword drawn.

EDIT: There are rumours that the FOV Mod fixes this issue, but as I'm not experiencing it, I can't confirm this.
It may be worth a try:
http://redkit.cdprojektred.com/index.php?c=mod&m=show&p=76