I Am Having Chills Then The Sweats, But No Fever.

I am having chills then the sweats, but no fever. Upset nauseated stomach and diarrhea. I had surgery on my broken wrist 2 weeks ago. I had taken Percocet prescription for pain and I was taking 2-3 Benadryl each night because I couldn't sleep for the pain. Prior to my surgery I had a productive cough with greenish phlegm...however the coughs have been limited to mornings when I get up. I feel awful with my stomach every day. Do you think I have the flu or common cold? I'm 63 yrs old and have had my share of both but this is really kicking my behind.
Thanks for any input.