Its important to rule out mechanical versus inflammatory back pain or infective. Few simple history and clinical examination can tell what type it is. If it is severe , as u r describing , then dont ignore. You need to visit Rheumatologist for this.
Next Steps
Few investigations like ESR ,
CRP and xray of the involved area followed by MRI of involved spine plus SI joint if needed
Health Tips
Monitor weight loss, fever or decreased appetite or other systemic feature.