Sounds like fur fever....I used to get like that, a deer would come by and I'd put the pins in the general area and let loose! My heart would pound a mile a second and I was breathing like I was running a marathon. lol
Before you shoot, think about what you have to do to make a killing shot. Determine what the yardage is and which pin youmust use.

What also helps is shooting 3D tournaments. It really helps youto get over the jitters. The first time I shot at a 3D target, I got the jitters BAD. Oh my God, that deer is looking right at me! lol.... You become more confident with yardage AND shot placement.