Lower Back Pain

So i injured my lower back deadlifting (going for one extra rep I shouldn’t have) 3 weeks ago. The week after I felt okay and did my warm up but it hurt toward the end so I stopped. then for the next few days felt extreme pain in my lower back and could barely do anything. A week later I felt good and did a warm up. Everything felt fine until I left the gym, then the same thing happened. ITs been 6 days since then and I felt fine this morning and went in and benched and hit my tris and chest. Now it hurts again, not as bad but still pretty bad.

I’m gonna take tomorrow completely off from deadlifting and try and come back next week. ANy idea what this could be? It hurts when I round my back or even arch it just standing up but when I bend over it kills. LIke I said it feels like it goes away and then its back. Any help?