Perhaps key here is ‘confidence’. It comes easy in youth. In age, we are given a different set of gifts. Now your ear may be more refined. When you play in a group, you always think you sound better than you probably do, playing alone. And perhaps now you have a higher standard of what you want to be hearing than you did as a younger player.
Whatever the problem, it can be overcome! if you are willing to do the work. Set small, reasonable goals. Look deeper at HOW you’re playing to improve technique and tone. William’s advice was most important of all. Never give up!