I started taking generic Zocor 5 days ago and I too feel like I've been hit by a truck. My neck is so stiff and I seem wide awake at night and have trouble sleeping. After doing some research I thought perhaps I had adrenal fatigue because I had most of those symptoms. I'm going to quit the Zocor cold turkey today and see if I start feeling better because it's difficult getting up and going to work. My muscles are aching and when I get up I seem to be stiff all over, even felt some weird chest pain this morning and lightheadedness. If this is how I have to feel on cholesterol lowing medication then I'll just keep my high cholesterol (258).