Use it and abuse it?
Do a quick count of all the shots you use in a match that you don't have very good technique with. Unless you are an elite top player, it should be a lot, right? Okay, now ask yourself: Do you have a better chance of fixing these shots by A) playing matches, where you'll continue to use these shots and re-enforce poor technique; or by B) working with a coach and only using the shots there and in practice sessions, where you can focus on doing the shot properly, and playing matches only after you've fixed up the technique? If you answer A, then good luck fixing the problems. If you answer B, then you are on the first step toward fixing your shots and dramatically improving your game.
This doesn't mean you shouldn't play any matches until you have perfect technique. You need to find a balance. But every player without perfect technique (i.e. everyone) who wants to improve should sometimes take time off from match play and for a time - weeks or months - just practice proper techniques.
So make a list of shots you use where your techniques is not good. Find a block of time - at least a month, maybe more - where your focus will be to fix these problems. Avoid matches during that time and just practice to fix the problems. Do a lot of shadow practice during this time to re-enforce the proper technique. When you feel you are ready, start playing matches again. You'll come out way ahead in the long run.
I blew it!