There are a number of things to consider in my opinion.It is certainly wise to make adjustments one at a time and to go back to where you started from if you do not see the desired improvement.Years ago I made sweeping changes that at the time were very hard to adjust to,I had the assistance of professional instruction and a very close friend who was a very accomplished 3d and indoor shooter.The point being,I had a safety net and lot's of available support to help me through the major adjustment.
I certainly have my beliefs as it relates to form,and I wouldn't attempt to or suggest to someone what they may be doing wrong without physically being in their presence or seeing a number of photographs of them at full draw.I would recommend that you get to someone who really knows their stuff,whether a pro shop for target archers or a trusted friend who is an excellent bow technician and have them help you.Getting set up correctly is the first thing you need to do,then you can deal with what may be the mental aspects of shooting.
I feel for you!It sucks when you are not comfortable and confidant about your shooting.Good luck!