Welcome Ruby Garcia
I am not sure what a "TAC" is?
Hopefully you've pulled/strained muscles in your back, but if it is so painful that resting doesn't help perhaps you should ask your Dr for an MRI. Sometime x-rays alone will not show all that is wrong.
If your taking muscle relaxers and pain meds and it still continues this long I would certainly suggest you see a specialist to make sure it's nothing serious.
I'm glad you found this back board.
please keep us posted and I hope you feel better soon.