"Follow your passion" sounds like good advice until you actually try to use it. Most people don't have one clear passion sitting around waiting to be followed — they have a handful of loose interests, none of which come with a job description attached.
Here's a more useful question: what kind of problems do you like solving? Not what do you love, but what keeps your attention when things get hard. Passion is a feeling, and feelings are unreliable career compasses — they show up after competence and momentum, not before.
Instead of hunting for a passion, look at your last few years of work. Which parts did you keep choosing, even when nobody was watching? That pattern is worth more than any single moment of inspiration.