Worse Before Better
OK - apologies first. I am deeply sorry, but everything you read in this site will wreck your game; at first. It isn't my fault. It is the nature of athletic training that any significant changes in technique, even very beneficial changes, result in a period of overall disastrous performance. This phenomenon is called "worse-before-better" or WBB, and it is a truism that is well known to coaches, physicians, economists, systems analysts and politicians. It results from the disruptive effects of improvement on complex systems. As there is no more complex system than a tennis game (other than, perhaps, a golf game), it is not surprising that the immediate effect of improved stroking techniques is to tear one's game to shreds. The inevitability of WBB is one of the main reasons tennis players don't improve their games - the process is painful at best. There is also the problem of differentiating the temporary ill effects of WBB from the more permanent disability engendered by the "black pearl," i.e., a tennis tip that is just plain wrong.
In fact, it is actually fairly easy to differentiate a good change precipitating worse-before-better from the pernicious effects of a black pearl, but unfortunately, differentiation requires patience. Patience is a virtue that has been stripped away from all of us in a society wherein the rate-limiting speed is the speed of light along a wire. Nobody wants to learn a skill, practice it, then use it in play for a few weeks to see how it goes. Patience is the process, and there are no shortcuts. Natural selection chooses black pearls that can improve our games, albeit in a very narrow context and for a very short time. You must expand the context and time frame to see black pearls for what they are. A valid prescription will gradually improve your results as the motions become automatic, and you find a place for it in your overall strategy. Increased pace, for example, can be more trouble than its worth; increasing the conspicuity of errors and permitting your opponents to reflect your power back at you. In time you will make fewer errors and learn when to unleash that new pace. Dealing with worse-before-better is trivial once you understand and accept the concept.