The first place I would look is set-up. Make sure that you are giving yourself a chance. Get clear about the type of motion you need to produce. Practice it in the mirror. You have to focus on your motion to improve. You want to turn off the part of your brain that is judging or concerned about what other people might think. My suggestion is to get away from anyone else. Practice where no one else can see you, then give yourself a break. Be patient. Golf is about the journey.
Clearly picturing a bad shot will often result in a bad shot. When this happens, you should acknowledge that you did a good job of translating your picture to your execution. So you need to get better at making good pictures. Often, technical improvement will help. You will find it easier to hit good shots. You may also have to spend some effort training your brain to see better pictures. One trick I use is to picture what a particular great player would do in the situation and try to act that out.