What Could Cause Recurring Severe Illness, Ongoing Back Pain Near The Kidneys, Fatigue, And Chills?

Two years ago in April i become vary il we thoth it was covet after all the test were done i was negative ,dr;s told me it was a wirus but wasent covet in august it repited ,was also very sick all simptens were Corona virus ,had tested it wasnt came back negative sinse thes i been sofering with cold back even two sides like kidnay area ,in deember of last year dec.23 i had a buster shut two hours latermy head was gono blow apart tre days my fever never cam down jet i was shivering ,i was tested positiv wit Delta tre weck i was so sick ,folowd by luck of energy and extrimli freezig bakthe intire bak kidnis included please help me ,i would be very hapy with an answer I thank you al ...