Even at a 1 setting (the lowest), the mouse look speed is way faster than what was available pre-Dragonlands patch, and is too fast for me to play comfortably.
I can’t imagine how people can play this game at a current 5 speed value, much less a 10. You breathe on your mouse and your camera violently spins around.
Is it like this for everyone, or do I have some sort of mouse issue?
Have you changed your mouse sensitivity outside of the game? My mouse has a button on it by default that I sometimes hit on accident that changed my sensitivity. It will override whatever I have it set to in game.