That's possibly a simple case of the "new" carpet being over the old underlayment that the cats peed on. Stop with the candles, candle oil, cleaner, and freshener. You are wasting your time with worthless solutions.
First, call a couple of places that clean up messes, ask if they have a Wood's Lamp or UV light. Or buy a black light and a reflector yourself. Look around your house.
See if you can find any spots. If not, you may need to hire a plumber, check to make sure your drains work. Then look for anything that's rotting or decaying.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.