I totally get that!! I've struggled with disordered eating for a long time, which still impacts the way I tend to think about high calorie foods. what really helps me with this is:
1. actively think about and reflect why you feel this way about those specific foods. once you know the reasons, start to actively rewire what your response to that is. for me it looks something like: I notice a high cal count and put the item back. I stop myself for a second and second guess why I put it back. is it because I have been taught that it's wrong to be fat or to gain weight? do I support these lessons? what are my actual wants? and based on those questions I might decide to actually buy the high cal item. it's basically unlearning a bias you have most likely been taught all your life.
2. start thinking about high cal foods in a positive way, anytime you get the chance. for me sentences like "high cal just means this gives my body lots of energy. that is a good thing." or "there are no bad foods, you are allowed to eat what you enjoy" etc. really helped me to see high cal foods in a different way.
these aren't shirt term tips on how to deal with this, for me this has been a years long process of constant work on myself & my beliefs but it is so so worth it! hope someday you can buy and enjoy high cal foods easier!