I was bent over the freezer when i felt and heard something like a rubberband snapping i've had a fusion in my lumbar region?

Sounds like a pulled: Muscle, most likely; or scar tissue breaking. I don't think the fusion would have come apart. You should take some pain meds, rest the back, apply ice or hot packs, and do gentle exercises to the back. If symptoms are getting worse, then definitely see your doc for further investigations. I would think its a pulled muscle, and would be better in a few weeks. Good luck.