You cannot know whether or not you're passionate about something until you've faced and overcome resistance. Passion is found in the doing. You cannot be passionate about the idea of something. If you have not done it, if you have not encountered resistance, if you have not continued until you overcame resistance, you are not passionate about it.
What this means is you have a lot of auditing to do. You have to narrow down the over-inflated list of passions in your mind. It's time to examine that list and systematically remove the imposters.
Enter into an exploratory phase. If you have not spent time doing something that you think you might be passionate about, give yourself permission to try it. Allocate time to the act of doing. You're not quitting your job or making any permanent commitments, you're simply allowing yourself time to explore.
Just pick any one thing. It doesn't have to be the perfect thing or the right one. For the next several weeks or months, set aside time each day to practice, and learn, and do. Make mistakes. As much as possible, immerse yourself in this world. Take the idea of thing the you had in your mind and audit it. Try it and see if you like the act of doing it. Put yourself in the position of experiencing what it's like to do this thing. Get a good idea of what your day would look like and what the process would be.
Keep going until you encounter a significant challenge. Keep going until the novelty wears off. Your response at this point is key. If you are truly passionate, you will press on. If you only liked the idea of this thing, you will quit. You can't just be passionate about the idea of something, you have to be passionate about the act of doing it. That is what your life will actually be like.
You won’t know whether or not you love something until you’re on the other side of resistance. Being passionate about something doesn't mean there will never be times where you don't enjoy the work. There will be challenges to overcome.
Passion is the thing that will fuel your drive to persevere against all odds. When you feel like giving up and you're questioning everything, passion will carry you through. The rational side of your brain might tell you a challenge is too hard or you should quit. Passion is what will help you be unreasonable when you need to be so that you can persist when all other signs are telling you to give up. That is when you know.