Answer of Lama Ole Nydahl:
Fear is not a primary or secondary feeling, but a tertiary one. The primary, basic disturbing feeling is ignorance; from this, others arise such as confusion, pride, and anger. Out of these then fear arises.
Fear originates from old anger and resentment which come up again and which one cannot stand having in one’s own mind. If one has these disturbing feelings inside oneself, and one’s mind looks at its own content, then it will see things it does not like and experience fear.
The outer world is a projection of our mind. If we look through rose-colored glasses, the world is beautiful. If we look through black glasses, it is horrible. We will have fear if the anger, resentment, and disturbances inside us have not been worked out. The best way to get rid of fear is to very consciously wish all beings everything good every day, as often and deeply as possible. There is no fear that will not disappear then; the blockages that one cannot bear will fall away. Good wishes for others are the strongest antidote.
In the case of anger and fear, it is also very good to do one million repetitions of the mantra om mani peme hung. This mantra is like an all-purpose cleaner. Om removes pride, ma dissolves jealousy, ni removes attachment, pe cuts through confusion, me eliminates avarice and greed, and hung destroys anger. Whenever we say om mani peme hung, we clean the inner mirror of our mind. This is very effective!