I believe the only true way to "cure" buck fever is experience. The more you do it, the more confidence you build, and confidence is EVERYTHING.
One thing that did help me was shooting year-around, and with groups of people you don't know. Standing at a line with 20-30 guys watching puts the pressure on, which is as close as I've found.
The biggest thing you can do is to practice as much as possible. When I walk into the woods, I need to feel "deadly". You need to get to the point where shooting your bow becomes "automatic". You can't think at the moment of truth, you simply act on instinct. At least that's how it is for me.
I agree with everything Todd said. I don't do the shooting with 20-30 guys part anymore but it is a great way to get use to shooting under pressure. The rest, for me anyway, just came with experience. Davidmill makes good points also. Just try to focus on a spot on the deer. Whether it's a buck or a dow. When you decide to shoot, glue your eyes to the spot you want to hit and keep them focused there envisioning your shot hitting where you are looking.