I use to get buck fever to the point I would make a bad shot, but finally I got to where I'd ask myself "do you want to freak out and miss this buck, or calm down and concentrate?" I think realizing that I was lacking control helped me to do something about it.
Breath deep, concentrate, aim small miss small.

PS . . . .I just took up the bow so I'm unproven with it. I've hunted with a rifle for over 40 yrs tho. So as far as the bow goes anything I may say is just blah, blah, blah.