Sudden bad low back pain.

Hello, ive been training for some years, and im 23, male, 199lbs.
current template has been powerbuilding 1. Basically i did an rpe “audit” one day and realized i had been misjudging rpe by like 2 (undershooting).

i started recording my sets, during one of the deload weeks i started going harder, using my updated knowledge i started doing what felt much harder but looked kind of easy on camera. This was going “ok”. Come the next week i had normal volume again. I noticed after my session of deadlifts my low back felt like it was experiencing “DOMS”. I thought of it weird because i hadnt felt doms in like a year since returning to training. I carried on as per usual on monday, and after 3 sets of squats, i realized i couldnt bend over without pain. Reaching for plates, grabbing my belt felt horrible like i hadn’t experienced before. I cut my last two sets off, pressed like normal, then did romanian deadlifts with like 135lbs on the bar for a couple sets of 30. Each set the first 5 reps were slow and painful and then became fast and like 35-40% less pain for the rest of the set.

i am now kind of dumbfounded not really sure what to do next, or how to make sense of what caused this, a little worried for my next sessions. I would appreciate any advice/expertise, i didnt feel any kind of tweak or anything, it was just some mad soreness only a day after deadlifts it seems, that carried into 2 days later.

Have you read the “Pain in Training” articles and watched or read any of the low back pain material?

It simply sounds like you suddenly exceeded your tolerance/capacity, by pushing a bit closer to failure compared to what you had been used to.

I would manage this in a similar way to any other general ache/pain, as outlined here and here, and upon your return to training would recommend a more gradual progression in intensity / proximity to failure, rather than making sudden changes like that.

Thanks, i really appreciate it.