Need 2nd opinion ? lower left side of my back in the kidney area hurts and slight burning when i pee?

I woke up sunday morning after drinking pretty heavily saturday night and my lower back on my left side had a sharp stitch (around the kidney area). it is now wed and the pain is still there followed by a slight burn when i'm peeing and for awhile thereafter. I tried to get into my doctors but couldn't so i went to a walk in clinic. The doc made me do a pee test and told me it was clear and that i tore my oblique. that would explain the pain but not the burning. any advise on what this could be or if i should get a 2nd opinion from my family doctor would?? i'm worried it might be my prostate AND a tare in my oblique. Can you tell from a urine sample if the prostate is enlarged for infected?