How do I report on powerful people without being afraid?

You have learned to investigate, and that is the hard craft. The fear you feel now is not weakness; it is a correct reading of real stakes. Powerful subjects can push back, and the law is a real risk. Being afraid means you understand what you are doing. The answer is not to feel no fear. It is to make the fear do useful work: it should make you more careful, better sourced, tighter with the facts. Courage is not the absence of fear; it is doing the careful thing while afraid. Small step: build the habit of documenting everything and leaning on your editors and legal team early, not late. You do not stand against the powerful alone. Solid work and good backing are how the frightened do brave things anyway.