Your latest results before and after breakfast are fine. 5.1 fasting is very good, everyone eating shredded wheat with blueberries can expect a big spike at an hour. The secret is to be back down again (or as near as dammit) by about 2 hours. You did this, so that is also excellent.
Yes, it looks like your white bread needs to be avoided in future. Try a wholemeal with loads of seeds in it. There are low carb breads on the market. Bergen is sold in all supermarkets, Waitrose do one called Livelife, and Lidl do delicious high protein rolls that are very low carb.
Have you been told about the role of carbs in controlling diabetes? All carbs turn to glucose once in the system, so it makes sense not to eat too many. All bread, potatoes, rice, pasta and cereals are the main culprits, and diabetics also need to be careful with milk and fruit. If you want to avoid developing full blown diabetes, perhaps you should review your whole diet and seriously reduce/avoid these major carbs.