I was able to beat your kind of target panic in a similar way as you, but only temporarily. Instead of blocking the target with the riser so as not to focus on it, I would purposely draw somewhat higher without really looking at the target, allowing me to come to full draw. Then, I would allow the target to come into view and slowly align the arrow downwards towards it. This worked for awhile, allowing me to come to full draw, until I developed a new form of target - the kind that causes one to freeze away from the target, preventing one from lining up the arrow with the target even at full draw.
I've been working on just coming to full draw, then acquiring the target, holding, slowly pulling back, and then letting down without releasing numerous times. I sometimes let one fly, but I try my best to not to do that. The only time I'll release is when I do some blind blank bale to work on form, but then I always go back to the draw, hold, let-down exercise. I'll continue to do this in the hopes of getting better control of this TP.