From the symptoms you have enumerated, its difficult to deduce the problem. Has your doctor checked your lymph nodes? Fever only at night and lower back pain, points towards diseases like typhoid and malaria. But the tightness in your chest indicates that the source of the problem could be a pulmonary infection. Do you have back pains and experience shortness of breath in the day also, because that could help narrow down the problem your are facing? I recommend a sputum culture. Xray of the chest can also be done to rule out bronchitis and related diseases, but the culture should be done as soon as possible. Only once the results come can the disease be identified properly. As a precaution, dont eat or drink anything cold before you go to bed. Drink a glass of lukewarm/hot water before you sleep and gargle everyday. Feel better
Can you describe anymore symptoms you might have ? Are you coughing or a runny nose. There are many causes for night fevers. If you can elaborate we can likely figure this out. It may not be related to infection.
Did the first doctor listen to your lungs? Have you been tested for TB? Usually the fever goes up at night and you get fatigue and cough. But, also a chest infection would give you this high of a fever. So getting a sputum sample for culture to see if have an infection would be a good idea. Did you or do you have a sore throat too or just the lung symptoms? Did you ever see white spots or pus in the back of your throat? It doesn't sound like you had strep throat when they tested you for it. But they may have done it due to the high fever symptom and red throat. To test for TB the best test is called the Quantiferon gold test. But you could get regular TB skin test too if you never had the BCG vaccine.
Hello,
It could be a form of bronchitis. I know you do not want to spend money on tests, but in this case, you really sure, those symptoms really do warrant further investigation.