What a great question Katlyn! I think every diver out there has a fear of smacking. It hurts! That said, I personally don't believe you ever "get over" the fear of smacking. I think you have to work through it. You have to "go" despite your fear. The best way to help you with the fear is to ensure yourself that you know how to perform the dive. If you have done all the prep work to prepare you for the dive; if your coach says you are ready to try the dive; then you have to trust in your ability and just go! I wish there was a magic cure, but I think it just comes down to confidence and courage: Not lack of fear, but rather action despite of your fear. Here are a couple of guides on iSport that might help you. Good luck!

http://diving.isport.com/diving-guides/how-to-build-confidence-in-diving/
http://diving.isport.com/diving-guides/overcoming-hitting-the-diving-board/

Think of it as it really is. The worst that happens? You smack, it hurt for maybe ten minutes, maybe leaves a nice bruise if it was an exceptional smack. BUT, you get a new dive or get closer to it, and you have accomplished something new. Most people fear smacking not because of the physical pain, but because of the feeling of loosing control in mid air. You can't let it control you, and there is no reason to fear it. Hope that helps :)