Wow...sounds like you have your plate full.
Shampooing your carpet for an entire day is certainly enough to bring on an acute case of back pain. As it seems it's dragging on...and many aspects of your life are being affected i.e. sleep, activity, and going to the bathroom - you are wise to be getting tested to see what the cause is.
Since you mentioned the bathroom problems...two things come to mind. 1) potassium levels c/b dropping since you are going SO much and, 2) I w/b concerned about a possible injury to your back causing this. If that's the case, you really need to see a NS or another specialist ASAP. I don't want to scare you...but, there c/b issues w/ the cauda equina nerves. If you end up looking this up...it can be very scary...cuz it can be severe w/ severe long-term effects. I researched my probs....and tend to over-analyze everything...thought I might have that cuz I was going #2 alot everyday and lost weight. Well...for me....I was giving a HUGE Graduation party for my step-daughter and my nerves were in a fury! THAT was my prob. I've since gone back to regular and gained the weight back :( Just sharing that so you don't overreact. But, please,...don't underreact either. It might be that - and it might not. But... you definitely have something going on that requires a doctor doing appropriate testing. I would ask about an MRI.
Please let me know what you decide. Good luck and God Bless! :angel: