Everyone is right, don't give up. Practice, practice, practice!
When I look back at the first wedding cake I did, I can't believe how far I've come since then. My frosting is smoother now, my borders are more uniform, etc. Get a couple of small dummy cakes, and everytime you have some frosting left over from a cake, frost up the dummy for practice. You'll find that you're ready for another wedding cake in no time!