Hi,my Age 32 F,why Iam Feeling Very Tired N Not

hi,my age 32 F,why iam feeling very tired n not able to concentrate on my work n iam not able sleep n evry time iam feeling like not able to breath n my lower back is paining my legs are pulling n my family doctor did all the tests like FBS n PPBS n she told that all tests are normal n u need to take calcium,but all are saying that by taking calcium may lead to kidney failure is that true