What Causes Fatigue And Headaches After Receiving Steroid Injections?

I had some steroid injections done on February 16, 2015. Ever since then I have felt fatigued, headaches, and I feel as if I have a fever everyday but the highest my temp has been is 99.2 I was recently diagnosed with hypothyroidism. I have been taking my thyroid medication as instructed. What could be causing my symptoms?