Don't take this the wrong way, but I feel so pleased to know that there are other people out there with the same problem! I thought it was just me.
I also tried shooting with my eyes closed at a close boss which I found helpful, but also am now having difficulty opening my eyes - the very sight of the sights waving somewhere in the vicinity of the target is enough to trigger a loose, seemingly automatically. It's really buggered up my shooting (4yrs, 1st class).
So I've made a training aid: piece of dowel about 10" long, suitably notched at either end, and made a proper 14" bowstring witih loop servings, centre servings, nocking points, the whole kit and caboodle - so that it felt
real on my lips/chin/nose - the authenticity of the feeling was important. Got a broken arrow with nock, cut 3" off the nock end (to make a very small arrow), fitted it to the string, cut a one-sided depression in the dowel to accept the other end of the "arrow", securing it with a rubber band. I can swing the arrow out, unhook the string and slide on a loop of rubber shock cord/bungee cord. I have two weights/thicknesses of this, so can adjust the weight I am pulling against. Then the cord passes through a plastic grip (the sort you get from Wilkinsons for carrying shopping bags so they don't cut into your fingers) and I stand on the end of the cord - if I change the place I stand on and the knots either side of the handle I can further adjust the weight. I can come up to full draw with this contraption, looking my hall mirror and it feels like I've got a string and arrow against my anchor point - and just hoooollllldddd it there. As I'm still struggling a bit, my next refinement is to fix (somehow) a sight pin on the plastic handle, so I can aim at the small target I've got sellotaped to my mirror, so I can practice putting the sights on the target and wwwaaaiiitttiiiinnnggg, rather than the sight picture of the pin-on-target being the signal to loose. I really feel this has helped. If I could post an attachment here, I would, hope this description has been of help. It was a very, very difficult job making a 14" bowstring - it kept twisting and I had to do it about 8 times before I got the angle right - oh, I forgot, I had a picture taken of me at full draw and I measured the angle of the string on my face - 135 degrees
, so I got that right to increase the authenticity of the feel. I might investigate getting some proper wooden grips to similate holding my bow.
regards