Hello: What Is The Difference In Efficacy And Side Effects

Hello: What is the difference in efficacy and side effects between Crestor and its generic? I went from 5 mg/week of Crestor (up to early November 2016) to 5 mg/week of the generic since then. Since mid December I am feeling weak and tired. I was on Crestor for several years and did not experience such weakness/tiredness.
The current feeling of weakness is very similar to the Lipitor I took 10 years ago or so, which I did not tolerate well.

I should mention I had a bad winter cold from Dec 24 to Jan 8 and now I feel almost completely recovered.

Greg