I Had The Viral Flu 3 Weeks Ago, Took Tamiflu

I had the viral flu 3 weeks ago, took tamiflu for 1 week, did not feel better, went back to dr. and was diagnosed with a sinus infection. Was given amoxycillin and prednasone. I am now on my last day of amoxycillin. I am tired, still congested. I also was given an increase of levothyroxine 2 weeks ago. I went from .25micrograms to .05 MG.
Could this also be making me tired? I am concerned about being so tired.