Good morning
@SuperCat and welcome to the forum.
You are clearly determined to tackle this and you have time to gather some useful information before your appointment with the nurse, which can inform the decisions that you take. As others have said your HbA1c is well into the Diabetes zone, but you have already read of others that have returned theirs to normal range.
With your test kit you can start to find out how many carbohydrates your body can cope with. This will be different for each of us. Test your BG before you eat and again 2 hours after a meal, by which time your level should be back to within 2 mmol/l (? Can someone correct me if this is wrong) of where you started Keep a record of this alongside the amount of carbohydrates you have eaten and you can start to make informed decisions about what to change. If your levels are too high after a meal you need to reduce the carbs, by making some swaps to lower carb options and/or by reducing the portion sizes.
Carbohydrates are in obvious things like rice, potatoes, pasta, cakes, sugar, … and also often loaded in sauces. I knew absolutely nothing about this before I was diagnosed, but once you start looking you soon recognise them. To find the amount in any meal you eat look at the info on the labels or use google ‘carbs in …’ . Ignore the ‘of which sugars’ bit. All the carbs will become glucose once inside you so it is the total carbs you need to look at.
Another thing that can help us reduce post meal levels is by doing some exercise. I try to follow the ‘don’t sit down for 15 min after a meal. This could mean that we go for a walk, or just do the clearing up before we slump, or a quick weeding in the garden. Whatever suits you.
That is a lot of info, but you have already decided to tackle this, so look around on the forum, take a look at the Learning Zine (orange tab at the top or in the menu) for lots of useful info. Also fire away with any questions that you have on here. There is a wealth of experience to tap into. No questions are considered silly on here. Just ask.