Anything mechanical that I have tried will work for awhile, but end up going down hill, and often will result in a poor release.
Try this, it works the very best for me, I draw, and then pick my spot, then let everything settle as far as my sight picture goes, this takes around 2 seconds once at full draw, not until then do I start a 4 count, (Onethousand-one,Onethousand-two,Onethousand-three,Onethousand-four)
Most of the time I can get through the one thousand-one before I release if I am concentrating at my best, I then keep my bow arm in place through the 4 count, and in fact after the release and the arrow is gone I bring my bow arm and sight picture very slowly back in to alignment just as before the shot. Think of the whole process as an art form, and do it the same each and every time.
I have struggled with target panic for years, and this system has seemed to beat it for me.
The key is to not start the four count until I have been on target with my sight picture for a few seconds, at that point, if I release earlier in the 4 count then usual, in my mind I have already beat the target panic, and don't fret about it.
What I find is that under stress situations, such as when shooting at game, I might realease right at the beginning of Onethousand-One, but even if just in target practice if this happens, I don't worry about it, because in my mind, I have been able to stay at full draw for a few seconds, thus I have conqured target panic.
Do this system long enough, and you will find you will be able to stay at full draw for 10 seconds if you need to, such as if when coming to full draw on a live deer in motion it suddenly stops for several seconds just as the vitals are hidden by a tree, but yet you can't let down without being busted.
For me I stress to myself in my mind the statement "Full draw is a place where I am relaxed in an uncommited state of mind"... to me that means, until I begin my 4-count!
I got parts of my shooting system from the Rick Welch video, such as holding for a time and letting my sight picture settle. I know there are many out there that say a dead release is not a good thing, but for me I am sold on it. Rick Welch is a world class shooter, and I have seen video of him even let the arrow slip forward ever so slightly and still hit the mark. So like anything, there are many ways to be successful doing the same thing, there are alot of great archery shooters out there using different styles. I believe this to be the best way to beat target panic. I know in the video Rick will say hold, hold, hold, but for me this just didn't work, it was not till I let that space of time lapse before I began my 4 count that it all clicked. Like anything, this also will take time for you to master, the only other important thing, is to start this or any process you decide to try while only about 5 to 10 feet from your target, the closer the better, for some reason it is easier to learn a good shooting process at a very short distance to your target. Then once mastered, I would still shoot at least a few shots somewhere in your practice session at a very short distance.
I have had target panic so bad in the past that at my worst, I could not pick my bow up without shaking and breaking into an instant sweat, so belive me when I tell you I know what target panic is all about. It is an ugly thing, and it can drain every ounce of joy out of archery.
If you want to B.S. about it a bit feel free to drop me a PM and I'll get my phone number to you. DK.