Yep, your bow is fine. It is all in your head. I'm a firm believer that archery is 90% mental. Just clear your head, remind yourself to relax and have fun. When you start getting tired, quit for the day and do it again tomorrow. It will come back. Repetition, clear your head, float, and sqeeze. Chances are your thinking of 'getting worse' instead of the current shot. Relax, have fun, and it will come back.