Low back pissing me off, had to reset and it still interferes

[grand666]

I'll try to keep this short.

I did a mud run on the 5th of May. I must have tweaked my low back somehow because when I arrived home it started to get "stiffer" and by morning I felt like a 90 year old lady when I stand up. I didn't work out that following day.
My next workout it was still screwing around. I figured it will warm up etc. I took 10lbs off my squat and had a hard time when I came to 4reps. Took another 10lbs off and same thing. I left the squats because my back started to hurt. Finished with Presses and Deads, I deloaded on Deads too.

So, the following day and up till now my low back is still acting up. I squated 225lbs today with a belt and Deadlift with a belt, but still have the same feeling. I can't describe the feeling, it doesn't feel like it's the spine itself, like the bones, but more lower like my pelvis or something. I attached a picture to show where it hurts.

My job is 12hr shifts and I sit the whole time. I do get up now and then but when I do, it's like everything is stiff is shit. I hunch over and straighten out, stretch a bit then it looses up.

I'm not sure I hurt it or not, or if it's the lumbar spine. It feels lower than that.