I have had this happen years ago. It’s basically a small tear in the cartilage between your ribs and floating ribs. It’s a sharp, agonizing pain and dull ache that randomly come and go. It’s awful and takes a long time to go away like all soft tissue injuries.
My coworkers encouraged me to go to a Dr as it was an unidentifiable chest pain, and I’m glad that I did. I had never heard of this before, so I was relieved that it was a soft tissue issue and nothing cardiac.
I remembered a few weeks earlier, my much larger and stronger cousin snuck up behind me and ripped me into a half-nelson. I was not expecting it at all, made me feel like a frail old man, lol.
You should definitely get an official diagnosis to rule out anything more serious. As far as treatment, I’d try topical anti inflammatories, CBD or something like BPC157.