flu, sinus infection, pneumonia and I'm still stick

I had the flu 1 1/2 months ago.  I went to doctor after three weeks because I still felt terrible.  I had a sinus infection, swollen lymph nodes and was put on Azithromycin.  I went back to Dr. after 10 days because I still felt sick.  Sent for chest x-ray and had pneumonia and was put on Avalox.  I still felt sick and went back to Dr.  I was told bacterial infections were nasty and it would take another two weeks before I felt better.  It is now over a week later and I came down with a cold two days ago.  I am so depressed.  I'm sick of being sick.  I am exhausted (physically and mentally).  What's going on?  I think it may be mono?  Any suggestions?  Donna