I'm sorry to hear about the severe muscle spasm and pain you're experiencing. This sounds quite distressing.

For immediate relief, you should:

• Avoid any heavy movements or lifting to prevent worsening the spasm.
• Apply cold compresses to the affected area for the first 24-48 hours to reduce inflammation, then switch to warm compresses to relax the muscles.
• Over-the-counter pain relief and muscle relaxant medications like Flexura D Tablet (which contains Diclofenac and Metaxalone) can help reduce pain and muscle stiffness. However, this medication requires a prescription and should be taken only under a doctor's supervision.
• Stay hydrated and try gentle stretching once the pain subsides.

Because you are unable to change posture or walk due to pain, it is important to seek urgent medical attention. Severe muscle spasms with such immobility may require professional evaluation to rule out serious injury or complications.

Please contact an orthopedic specialist or visit the nearest emergency facility promptly. If the pain worsens, you develop numbness, weakness, or bladder/bowel issues, call emergency services immediately.

Taking prompt professional care will ensure proper diagnosis and treatment for your condition.To narrow down potential causes, we will need some more information.I am sorry to hear about your back pain. Please tell me your age and gender.