[Question] What could be the problem if my back suddenly hurts so much that it is difficult to even move?

For the past few days, I have been feeling some pain in my lower back, if I should describe it as a slight throbbing sensation.

Two days ago, when I was about to have dinner, I was sitting down and when I tried to stand up, the pain was really severe.

It felt like my lower back was suddenly pulled out, as if a connected pipe had come loose, and the pain was terrible.

I managed to move with great difficulty to eat, but even with assistance, taking a single step was not easy.

I lay down wearing a back brace I had at home, and it did get a little better.

I haven't been to the hospital yet, so why is this happening all of a sudden?