RE: cant stop the buck fever
...Hmmm, ah yes, the dreaded "melt down". Been there done that. Of course as has been mentioned that intense moment is one of the big reasons we love this pastime like we do. Exposure to these type of situations is the best medicine but you still have to have a "game plan".
Here is a somewhat brief description of what life and hunting has taught me about our dilemma. One's emotions will not listen to reason! Doesn't matter if it is intense fear or excitement, your emotions if unchecked, will always override good sense. Those same emotions will however respond to action.
Once the decision is made to harvest the animal, have a strategy worked out as to how you will execute each action that needs to be taken to achieve a quick and humane kill. Then follow that "blueprint" step for step until the animal is recovered. Let's say you spot a buck approaching and are confident the route he is taking will bring him easily within range of your stand. In this senario I have known people that have already hit the power switch sending 20,000 volts of raw adrenaline surge through their system and they have no "plan of attack" for pulling the shot off. In doing so they set themselves up for failure. They have no method of how they are going to attain success, just point and shoot.
Plan your work, work your plan
As the animal approaches know when you are going to stand up (if you must) especially if you are caught off guard and surprised. In your mind you could say, when he reaches this obstruction I am going to stand, position myself for the shot, and hook up! (that could be step one, or it could be step one, two and three, it is all in the way you set up your "scheme". Whatever the case, once done, focus your concentration on executing your next step). When his head goes behind this tree, I am going to draw (That accomplished, move to the next hurdle). When the deer reaches this position I will bend at the waist and stop him with a grunt (next step). When the deer stops, I will pick out a hair and drill it! (next) I will follow through on the shot, I will not drop my arm or peek but remain rock solid(once accomplished, move to the next step)....
This system takes some practice but is proven. Again, emotions respond to action not reason. It will not take away buck fever, but it will assist in "managing" one's emotions so you don't suffer total meltdown. Visualize yourself going through these actions step by step (including making the kill) over and over. Focus on how well you can perform each step and not on the deer, and you will go a long way to overcoming the "fever". As the saying goes, "you can't make the butterflys go away, but you can get them to fly in formation."
Everyone's "system" will be a little different, but it is the execution of actions that ultimately spell success.