I Started Taking The Generic Rosuvastatin 20mg About 2 Weeks

I started taking the generic Rosuvastatin 20mg about 2 weeks ago. It replaced Crestor that I had been taking for years. Monday, I had slight problems with loose bowels, since then I have been very tired (weak feeling muscles) with some headache. I am hungry, but nothing is very good. If I eat, I suddenly feel bloated. My neck is sore or tired, but not my throat. Can these problems be caused by a generic, since I never had a problem with the Crestor?