Symptoms After Flu Vaccine

I had my flu vaccine about 2.5 weeks ago in SEP.  On August 4th I completed 5 months of chemotherapy (topotecan) and my CBC was fine by the time I had the vaccine which was encouraged by my oncologist and forced on me by my workplace.  I had just finished 10 days of septra, also, for a sinus infection just prior to receiving vaccine.  I got my shot on a Friday.  By Saturday night had body aches and of course the arm in which I received vaccine was very, very sore. By late Sunday afternoon I experienced some shooting pains in my arms & thighs. Since then, I have developed extreme fatigue, weakness, joint aches, & just want to sleep constantly.  Also, I feel shaky sometimes when ambulating and notice that I have been bumping into things frequently.  Sometimes when I turn my head while ambulating I feel dizzy & out of focus for a moment as well.  I feel pretty awful; having a hard time being focused, wakeful, and concentrating.  What is going on?