It may help if you understand that there are two different forces at work here, requiring two different solutions. It is possible that some people might suffer from both at the same time, but let's look at them separately.
The first is what you suffered from when you went to the indoor meet: pressure. Your conscious mind went into overdrive because of everything going on. Your mind was bouncing around between what should have happened on the last shot, what should happen on the next shot, and what might happen in some imaginary place out of time. Everywhere but the present, where it needed to be, so you clutched. The only way you can shoot in the present is to stop thinking about everything and start becoming aware of what your body is doing on a physical level. It's okay to think before and after the shot, but not during the shot. There are all sorts of relaxation and self-awareness techniques you can use to help you with this, some of which you may have found on your own.
The second is target panic, which is caused by the subconscious mind wanting to get the shot over with. This is probably what Tyler has. All the relaxation and self-awareness techniques in the world won't help with this one. The only technique that works is to exert conscious control over the shot just prior to the release. Joe Turner's technique works for me as a way to do this. You draw the bow without any intention of shooting it until you get to full draw and everything feels okay. During this time, you expand your awareness to the max, and if anything doesn't feel right, you let down the shot. If you get to full draw and everything feels okay, you aim and give yourself permission to shoot. Then you mentally flip a switch and concentrate your focus on two items only: focusing on pulling the bow until your psychotrigger goes off, while looking at the target to hold your aim. Your psychotrigger can be a clicker or feather touching your nose or lots of other things as long as they aren't under your direct control. The psychotrigger is an important tool that allows you to take control away from the subconscious, but it won't work unless the final few seconds of the shot are under control of the conscious mind. If your mind is on autopilot and you're just waiting for he psychotrigger to go off, you'll still have target panic.
Again, you expand your awareness during the time you're drawing the bow until you come to anchor. Then, if everything is okay, you narrow your attention down to just two items: pulling the bow and looking at the target until your psychotrigger goes off. These 2-3 seconds are when you really have to work on maintaining conscious control of the shot in order to defeat target panic. Saying a mantra, like "keep pulling," during this phase helps to avoid extraneous thoughts and keep the shot under conscious control. You don't want anything happening on auto-pilot during these last 2-3 seconds. You have to have enough control to let the shot down rather than release it prematurely if it starts to collapse.
This is a very brief overview of Joel Turner's method, but it may give you an idea of how it works.