Vytorin and memory

My Doctor prescribed Vytorin becase my LDL was high (160), about 1 month ago. At the beginning, I didn't feel anything, but gradually I have been feeling stiffness and pain in all my joints and an incredible pain on my left shoulder, extending to the arm giving it a burning sensation. My mood has changed. I'm more irritable, depressed and my memory is worse than ever. I can't enjoy reading anymore because is very difficult to focus. My appetite increased enourmously and I gained 5 pounds since I'm taking Vytorin 10/40 every other day. I just read in this site that many people is experiencing the same side effects, so tomorrow (Monday), I'll notify my doctor I'm going to stop this poison. Iread in other websites that it causes muscle destruction and inhibits the synthesis of cholesterol in the brain, needed for well functioning. Who approved this crazy drug?