Hi Rich, I wouldn’t get too down on yourself, I lose and find my swing every few rounds (9 index), it comes and goes to an alarming degree, you just need to have patience and keep working away at it, I’d say the same applies for all golfers in the 7-27 range.

You’re only a year playing, and probably made significant progress at the start, you need to accept that the next phase won’t be a straight line, it’ll zig-zag on the graph but hopefully the trend line will continue to improve.

It’s very unlikely that lesson destroyed your swing, it might just feel like it has. As Jonathan suggests, if you find a coach that will make incremental tweaks to “what you have already” rather than changing it completely you’ll be far better off.

To get back on track yourself, do some practice where the shot outcome is irrelevant, e.g. make a line in the practice bunker and try to hit that line for your ground contact (no ball) or use a divot board or go the beach. Use a dry erase maker to put a red dot on the ball and hit into a net to work on face contact. Stick an alignment rod in the ground a few yards in front of you on the range and try to start the ball left or right of it. Practice trying to hit hooks, slices, and thin shots so you know what the extremes feel like. In short, forget about the swing mechanics, ask your body to perform a task and then get your mind out of it’s way. You’ll find a swing that’s uniquely yours, and hopefully a coach that will make incremental improvements to that swing.

There’s lots of books I could recommend (really depends on what you’re into to): Adam Young https://www.adamyounggolf.com/the-strike-plan/ for ways to train for impact and strike issues, Jon Sherman The Four Foundations or Zen Golf for expectation management. Happy to have a chat with you sometime if it helps.