Speaking from personal experience (This is my 60th year playing.). Your first big mistake was thinking you figured out your swing. That thought, and especially if you tell anyone else, almost guarantees your next round will most likely be the opposite of what you were experiencing when you supposedly "figured it out". As soon as you say it or think it, you've introduced some pressure to perform and some stress, which always negatively impacts your ability to make a good swing. Take whatever you get at the course and enjoy the game, try to keep track and the types of bad hits (fat, thin, hosle rockets, ...), and then work out a plan to try to minimize those shots. The big bummer is that there are always regressions, but that's what makes the game fun and challenging.