Even your income is probably relatively fixed. That's not necessarily a bad thing. When a relationship works, that's what you get. What we have left is the baggage of your life, your children, your mortgage. You could still go on for forty or fifty years, without ever feeling passion for each other again.
Some people think that is magnificent.
You should hang in there and try to work it out. Or you could dissolve the relationship. But that's pretty depressing too. But these are just songs. People write from the heart, but they also have an ear for rhythm and an eye for strong imagery.