Zocor and head constant

I am 38 years old, put on 40mg Zocor 3 months agao because of high cholesterol. While it lowered my overall numbers, I started having a fuzziness in my head, not sharp minded, fatigue. I exercise 4x a week and was losing energy. At first, I associated it with stress until my stressful project was finished, doctor upped my dosage to 80mg and it hit me, it was the Zocor. I have been off for 10 days now, headaches still there, but hoping they will go away. If anyone has thoughts, let me know at build2suit@excite.com