You have target panic my friend. Straightarrow and Tfox have it correct.

Get a multiple spot target. Lift your bow and look at the spot you want and draw your bow aiming at the target. Don't take your eye off the spot. DO NOT put your finger on the trigger! Look at the spot until you can get the pin on it, then hold it for a few seconds. Now let down and relax for a minute or two. Now do it again, but aim at a different spot. Do this for a while, as long as you comfortably can. Letting a bow down is harder than drawing one, so you will get tired faster. After a few tries you will calm down and it will get easier to get on the target and hold steady. Once your brain figures out you are not going to release an arrow it will calm down.

This combined with blind and blank bale shooting should help you out quite a bit. Like said though, it takes time, don't rush it. This is not something you will fix in a few hours, more like day or weeks[&o]. It may never actually go away. You might have to work at it constantly in order to keep it under control. Target panic is sort of like herpes, it never really goes away[:@].

Another thing that might help is switching to a different type of sight. Try and find one that instead of having a pin you put on the target has a circle you look through at the target. This works very well for target shooting, never tried it on deer though. And you won't find a multiple pin target like this. I it will have to be some sort scope type sight or something with an aperture on the end of a rod.

I have this form of target panic and it SUCKS!!!!!!!!.

Good luck,
Paul