[gchappel]

You can not feel a bulging/herniated disk from the skin, there is no lump. If you are actually feeling something- it is not the disk- it is something else.
This sounds like a significant change- so I would see your doc.
If imaging is warranted MRI gives a better look at the disks. If it is a compression fracture either will visualize it, although our interventionalists prefer MRI for kyphoplasty planning.
I would not try treatments before you actually know what it is.
I would not delay seeking treatment, you will not start to get better until treatment begins.
gary