I'm terrified of answering the door, is this normal?

Whenever the doorbell rings I get really scared and hide until they go away. I'm not afraid if it being somebody out to get me, but mostly salespeople, or beggars asking for money because I'm afraid to turn them away. When I was a kid (before caller ID) I could NEVER answer the phone. What are some ways to overcome my fear of answering the door, and does anybody else have the same problem?