As someone who thinks I don't fear anything, sometimes when I pass through an event, I'm very scared. E.g I'm surrounded by 9 dogs, someone want to agress me etc..
You could try progressive exposure. For example, if you're afraid of heights, stand on the first step of a ladder until you're comfortable. Then later the second step, etc.<p>Alternatively, you may find that being acutely suicidal removes a lot of your normal fears. Not recommended, obviously.