What Causes Severe Pain In The Upper Left Back While On Advil?

Question : I am 73 years old and live in Brentwood 94513. While visiting in Simi Valley - (I am a very active person) I walked 4 miles in 90 degree extreme heat. I do this all the time and yet one week earlier in Simi I had similar reactions while also walking in 90 degree heat only this 2nd walk brought on more severe results. While walking my nose kept running uncontrollably - I was coughing and becoming hoarse and had to keep clearing my throat. When I arrived back at my destination I was extremely tired and had to sit down. I was shaking and got cold chills and goosebumps but drank 3 glasses of cold water. My throat started to constrict and I had my husband walk me to the bed and help me lay down. I had severe pain in my upper left back - like a huge muscle cramp and pain under my left breast. it was all very painful but finally as i rested it started to ease up. I took an Advil and 2-3 hours later we went to the pool and I got into the hot tub (no jets) in hot water. But I was so extremely tired. During my sleep that night I woke up around 2-3 am and the pain was pretty severe again but I took another Advil and it stopped. Now it is back again as of last night and today and I am coughing. I called my doctor but he is out of his office for 3 weeks. I am OK laying on my back or right side but it is painful to lay ion my left side. No pain in my arm or neck. The previous day before the walk I did an extremely hard water aerobics workout in the pool. We also went to dinner and had wine. In XXXXXXX I was bitten by a cat and almost lost my right hand and ended up with C Differ 3 months after being released from XXXXXXX Muir Hospital in Walnut Creek. The C Diff was extremely severe due to the fact in order to save my hand I was on heavy doses of IV Antibiotics for 7 days every 6 hours. Joann XXXXXXX

No pain in back - just under left breast - and to the left side. When bending forward or taking deep breath or lying on left side it hurts and yes it is tender to the touch of I press on it at side or under my breast around rib area. No abdominal pain or nausea or vomiting. Had a previous episode in Simi Valley 2 weeks ago but no pain in chest or side or back - just got weak from walking in 90 degree heat for 5 miles and almost did not make it back to destination but after sitting and drinking water I stopped shaking and cold chills went away but I did experience nausea a little bit and felt faint. Was tired remainder of the day but felt fine once rested for 30 minutes. I feel it is allergy and stress related from heat and my lung and muscles are not happy with being stressed to the XXXXXXX in the heat with no shade to protect my body while walking fast 17 minute miles. I was worried possible heat stroke or maybe heart issues but I am very physically fit although I di carry the Epstein Bar Virus and had an episode in the spring for 2 months and then the cat bite on top of that and the C Diff. I am sure my immune system is not real strong after all of that going on