Your symptoms suggest nerve irritation in your lower back, commonly known as sciatica, which is often caused by a herniated disc or joint wear. Your medications, calcium with vitamin D, low-dose prednisolone (a steroid), and pregabalin (for nerve pain), are designed to reduce inflammation and calm the irritated nerve. The relief is only partial because 5mg of prednisolone and 75mg of pregabalin are relatively low starting doses. Additionally, medication manages symptoms but cannot physically correct a mechanical nerve compression. I recommend consulting your doctor to discuss a spine MRI, physical therapy, or safely adjusting your medication dosages to target the root cause.