Sorry about your pain, but man, you have a loaded situation. Couldn’t diagnose it and wouldn’t if I could over a forum. When in doubt, get it checked out - by a professional. Seeing a good diagnostician will likely be the fastest way to get the result you want - eliminate pain and get back to high performance.
However, let me put you onto a few ideas.
1. Herniation is a possibility but your not getting other symptoms usually associated with one. Usually we look for radiating symptoms into the leg like pain, numbness, tingling, and motor dysfunction - i.e. trouble walking on toes or heels, or contracting a muscle and weakness.
2. More likely, you sprained/strained the low back. This, like in an ankle, creates an instability and/or misalignment of joints and thus its treated as an instability by the body. This can cause a spasm, weakness, and pain or all three.
3. Specifically, the Sacroiliac joint or SI, is likely involved and is sprained/strained and misaligned. This causes big issues as the pelvis is integral to all movements in your life. Being off balance will load this joint and cause no end of discomfort.
Remember, pain is not a great indicator of injury severity nor is the absence of pain a good indication of having no injury. Get it checked out so you don’t injure long term issues that can haunt you later in your training life.
As I said, its prudent to get someone’s hands on your back to figure out if you are having alignment or nerve issues that are possible red flags. If you can give me your zip code or nearby landmark, I can search for qualified therapists in your area - at least one who I would have my athletes go see when they can’t see me! :).