Ok, so it sounds like you haven't really made many changes to your diet so I am guessing that you have perhaps buried your head in the sand a bit since diagnosis, which may well be why things have progressed and your levels are now higher.
I also feel that I don't want to contact the doctor because if nobody says anything or nobody knows then it's not actually happening.
This is not a good a good attitude as I am sure you know.
It is time to take control and put some effort into your diabetes management. It may be that you now need some medication to help as well as making dietary changes but regardless of medication, the lifestyle changes are important and can start now rather than waiting until your appointment with the nurse. Dietary changes can be extremely powerful in reducing your levels, more so than most oral meds if you follow the right advice and we can definitely help you with that here on the forum.
A couple of questions.... Do you have much/any weight to lose?
What sort of things do you currently eat and drink? Ie what is a typical breakfast, lunch and evening meal for you and what if any snacks? This gives us an idea of where you could make some simple swaps to improve things.
There are two main approaches that members here have found work well....
A short term very low calorie diet of 800 calories per day usually involving meal replacement shakes for 8-12 weeks to rid the body of excess fat and in particular visceral fat. You then need to find a way to maintain that weight loss which can be the hardest part, especially if you have a history of Yo-Yo dieting.
The other option is to adopt a low carbohydrate diet and this is a lifestyle change for life. Finding a new way of eating which is enjoyable but low in carbs. Takes a bit of getting your head around when you have spent a lifetime of filling up on bread and pasta and rice and breakfast cereals, but once you adopt new low carb eating habits it becomes progressively easier and what I find amazing about it is that you stop craving those high carb foods once you cut down on them and eat a little more fat.... The fat is important because it makes food more satisying, prevents hunger and provides slow release energy. In fact the focus on low fat foods over our lifetime may well be a contributing factor to our high rates of obesity and diabetes.... exactly what low fat products were supposed to help prevent. So things like having full fat milk and natural yoghurts and mayonnaise and cheese can actually help you to eat less and lose weight providing that you cut down on the higher carb foods. I know it sounds counter intuitive but I eat much less now that I used to and I don't feel hungry or get cravings like I used to, so it isn't difficult to stick to.
Anyway, a good place to start is making an honest food diary for a few days of everything you eat and drink and then see where you can start to make some cuts and substitutions. There is no judgement here as many of us were eating far too much of the wrong things pre diagnosis. One of the simplest things you can do is swap to a lower carb breakfast as many breakfast options are high carb (breakfast cereal/toast... even "healthy" options like a banana, fruit juice and porridge) These will all impact your BG levels to some extent. Making a lower carb breakfast choice can have a bigger impact than any other meal and because we tend to have the same thing for breakfast most mornings, it is an easy new habit to form. Many of us have creamy Greek natural yoghurt with a few berries (berries are the lowest carb fruits) and mixed seeds. I had stewed gooseberries from the garden this morning, with a little artifical sweetener as they are cooking gooseberries. Other times it is stewed rhubarb or raspberries which are my favourite fruit or strawberries or a few blueberries or blackcurrants or blackberries later in the year. The creaminess of the yoghurt takes the edge off some of the tartness of the fruit meaning you need less/no sweetener.
Anyway, that is just one idea but plenty more like scrambled eggs and smoked salmon or bacon and eggs and mushrooms, although I am not recommending people eat bacon or smoked salmon every morning. Eggs are great though and so versatile.