I know exactly what you're going through. I've had it for a long time, ever since I read one of "that guy's" books on instinctive shooting. It really started getting terrible a few years ago. I'm finally getting some control back, but I'm doing it by retraining myself away from shooting instinctively. Byron Ferguson's book "Become the Arrow" has been my inspiration.
One thing I've finally isolated is my grip on the bowchanges from what should be a relaxed, easy grip to white knuckles. When I consciously force myself to relax my grip, it's a lot easier to get a full draw and anchor.
Another deal that is really helping meimmensely is dropping w-a-y down in draw weight for practice. I highly recommend getting a bow that's ridiculously easy to handle, like a 25 pounder, and practice with that. That one thing has helped me more than anything else.
The shooting with my eyes closed routine hasn't helped me a bit. I can draw, anchor and execute a release as smooth as a world champion with my eyes closed, but when I open my eyes, everything goes to pot. I have to keep my eyes open and just force myself to relax, slow down and AIM the friggin' arrow. Three months ago, I couldn't get within 8" of my anchor before my fingers turned the string loose. Now I can anchor every time, but often still release before I'm really ready. It's getting better though.
Ted Nugent has aroutine he does that doesn't really seem to work for me, but it might for someone else. When he gets ready to shoot, he runs a saying through his mind. Beginning the draw: "In the name of the Father". During the draw: " and the Son" At anchor: "and the Holy Ghost" Then he releases on "Amen." Hey, the way I've been shooting, I figured prayer couldn't hurt, so I tried it.
My problem with that was I was concentrating so much on going thru the saying that I'd forget to aim.[&:]Might work better if I did something like "Draw: Anchor: AIM, YOU BUTTHEAD!: and Release.[8D]
Really, I wouldn't recommend going to a mechanical release. You'll get to the point where you just slap the trigger too early. You've got to retrain the brain, because that's the whole source of the problem.