Amalia,
I understand what you are saying about dreams. Sometimes they can tell us what is coming, I often have dreams of warning or something new coming. But your dreams are also about you & what is in your heart. Hiding your feelings isn’t healthy. And really, if he’s your best friend, I would be very surprised if he doesn’t at least suspect.
If you are meant to be together, then telling him how you feel about him will help move the process along. If he does not reciprocate your love, you will have to let him go, in order to find the person you are meant to. You can do that, if you are brave enough.
Good luck.