5 weeks post pardom & having kidney pain ?! Help so nervous!

I'm 5 weeks post pardom & have been having pain in my back on both sides, but mainly on my right & I think it may be my kidneys? I do need to urinate kind of a lot, & feel like my bladder isn't fully empty, but I've felt this way since giving birth and was told that that's normal? Now I am having pain in my kidney's I think? & im so afraid I have kidney cancer or something, I know I sound crazy but I have always had severe anxiety & I'm just assuming the worst 😓 I have a dr appt tomorrow & the nurse I talked to on the phone said these symptoms aren't necessarily normal after pregnancy! So now I'm driving myself crazy... Has anyone else had these issues after pregnancy? I know it could be a uti but it seems like I could have an infection? I'm so nervous 😓 how would I know if it was something serious with my kidneys ?