What to use for extreme. back pain?

See your doctor: Extreme pain is never good and you deserve to have that treated or at least evaluated. Always start with your pcp. If not available it's ok to seek care for extreme pain from an emergency clinic.

Get a diagnosis: Most cases I see are due to sitters disease or gait (ex; foot position). But you need to identify the origin and rule out more serious causes. Any neurologic issues like numbness in the legs, no muscle weakness, no fever, no urinary pain, fever, genital discharge, acute trauma, insect bites, etc https://www.youtube.com/watch?v=8TO8Il3vdxQ https://www.youtube.com/watch?v=t6SXiDCMP3E