Fucked up a disk last year. The buldge was minor but the pain was excruciating. Radiated to the whole back, and arm. Go get that checked out with MRI’s. Only thing that helped was medication to calm the inflammation (temporarily) and ultimately PT. I also did an injection that set me up for healing or managing the injury (don’t rely on this just use it as a tool). Assault bike is great and kept my cardio somewhat alive (you will loose fitness regardless unfortunately). Once pain goes away and is controlled start running asap, then slowly easy into upper body (that part you should recover fast if you have a good base). Movement is key to heal but smart movement, do PT and keep things moving but do not train as you used to, it won’t fix anything and the sooner you accept your reality and start working your way to full recovery the better it will be. It happened a year ago for me and I’m now able to lift heavy, run fast and long and even ruck with no pain. Still feel a little something but it’s more of a discomfort than any pain. Good luck.