Sudden Back Pain: What Could It Be?

it's weird, I had to stop sports 5 years ago because of back pain, was then diagnosed with degenerative disc disease, did physical therapy, and for a few years it died down. Now it's back worse then before, all of the sudden showed up a couple weeks ago while I was just walking around my house? had to miss out on work and can barely get dressed. but yea I'm going to physical therapy again and see what happens.