OK, it is terrible for you no doubt.
Can you get to the toilet by yourself, and can you get out of bed?
Just asking, because I tripped on the stairs last year and was like you. Totally immobile. Went to A+E they xrayed (no scan offered at all), and said it was nothing to worry about, ligament damage and gave me 5mgs of valium to relax the muscles. God I love that drug!
It made me able to sleep, and relaxed the muscles as they were in spasm. OH had to put one of the dining chairs beside the bed so I could slide out. I was in total fecking agony because my back spasmed so much I cried. And I could only walk with assistance, no more than ten steps from bed to loo. Was fkn awful, thought I would never be ok again.
I remember being so bad I bought Tena Lady pads so I didn't have to get out of the bed to use the loo!
Anyway after five days of this It did ease enough for me to take a few steps. Then more, then around the house (holding on to furniture for dear life!), then out the back garden for a walk (waddle) around, and eventually it sorted itself out.
My point is, if they have found nothing spinal it may be ligament or soft tissue damage and believe me that is just SO awful too.
Main thing is to keep moving as best you can, even a few steps every hour. The days of lying in bed are long gone now.
I am not saying you have similar, but you may have. Get the valium upped for starters. 2mgs is not enough to help the muscle spasms to relax at all. You need more.
Hope you will be ok my love.