Christ is risen!
The term “dark night of the soul” comes from St. John of the Cross. He wrote a poem of the same name, and then wrote two books on the spiritual life that used it as a structure: The Ascent of Mount Carmel, and its sequel The Dark Night of the Soul.
The basic idea of both books is that while you trying to improve in prayer life, love, virtue, etc., God is also doing stuff to help you. Sometimes God gives you lots of encouragement, special feelings of joy, and so forth. It’s a sort of spiritual treat and nourishment that is easy to digest. But then, as you “grow up,” God will often put you into a sort of training program for your faith, where you have to do a lot more work and prayer without having the happy feelings to help you. Often one does not feel the presence of God as strongly, or even at all. But then, mysteriously, you may find yourself suddenly having the good feelings again. This cycle tends to repeat in many people’s spiritual lives, and St. John of the Cross talks a lot about how to deal with the periods when God is stepping up your spiritual workout schedule.
People who advance very far into closeness with God will often have a “workout cycle” (or more than one) that feels very painful and confusing, where God seems totally absent and where nothing makes sense, like being lost on a dark night without stars. That is “the dark night of the soul.”
St. John of the Cross tells us that actually it is at these “workout times” that God is closest and doing the most to help us; but we can’t sense His presence because He’s working “behind our backs,” so to speak. The night is not really dark at all, but we can’t tell.
Now… obviously most people who use the term have not actually read both books; and so they often use the term to refer to either a time of failure and confusion in a person’s secular life, or for depression. But it’s not either. (Although obviously it can be depressing to not be able to sense God’s presence, or to have to rely totally on faith and not have any happy feelings about God!)
Do all Catholics go through this? No, but many go through periods when God is giving their faith a workout, and some spiritually advanced people do suffer dark nights of the soul. And yes, these sorts of things can happen at any time of life.
Some people never really have much feeling or sense of God’s presence, because it’s just something God gives or doesn’t give. Some very famous, devout, and wise people have been in that situation. Mother Teresa had a dark night of the soul that lasted over forty years, and yet it strengthened her to do amazing things.
My best advice is to read
The Ascent of Mount Carmel and see if anything sounds helpful or familiar. If it doesn’t, don’t worry about it. If it does, St. John of the Cross will probably have some helpful advice or insights for you.