Had sex then now I’m all of a sudden sick?

I had sex like almost a week ago. I think it was Monday. We went down to a creek in the middle of no where and had sex on the back of his truck well Wednesday morning I stated feeling sick. Wednesday I also started my period. I felt like my sinuses were messing up. Well I went fishing with my dad Friday and all day Friday Saturday and Sunday I was in the heat like all day. I feel like Iv been running fever, coughing up mucus, ears stopped up, kinda nauseated, last night I took a pain pill and Tylenol and my lower stomach was cramping so bad after I took that Tylenol. My period just stopped yesterday. My back, my side, and my shoulder hurts bad but that’s from all the movement from fishing. Suggestions?