Welcome to the forum
You probably only need a few adjustments to your diet, but people sometimes do have a misapprehension that it is just things like chocolate that is the problem and a small amount of a dark chocolate is probably less carbohydrate than a rice pot which not only has sugar but rice which is high carb.
Those food which have been pushed as being healthy options are not so for people with Type 2 diabetes or prediabetic where the body struggles to cope with all carbohydrates like bread, potatoes, rice, pasta, breakfast cereals, pastry, tropical fruits as well as the more obvious cakes, biscuits and sugary dringk including fruit juice.
In your case reducing portions of the high carb foods and basing meals on meat, fish, eggs, cheese, dairy and vegetables and salads with fruits like berries though apples, pears, melon and oranges are probably ok in moderation.
Have a look at this link for some meal ideas which would be low carb.
https://lowcarbfreshwell.co.uk/