Hi there. I think you are going to Dafne right?
1 Your hba1c at such an early stage won't have longer term impact as complications take longer to develop. You might feel rubbish though and you are spending time worrying about it so that is not good.
2 As type 1s we are sold a myth IMO that it is possible to eat as many carbs as you like, as long as you calculate the doses right. In reality there are estimated to be 150 variables that go into a blood sugar result NOT just carbs injested although that's obviously a biggie. So I try to do the best I can and eat low carb for health and weight management plus I am too lazy to do what I was told on Dafne and weight out foods then do the sums to calculate an insulin dose 20 minutes ahead of a meal.
In summary i think this approach works if you live a very consistent kind of life in which activities and meals are highly regularised. I don't live like that so I have to accept a bit more variability in my blood sugars but that's my choice. You will have to work out this one but at least Dafne will give you tools.
You should not feel guilty about the failure to keep to that initial HBA1c. You are learning about all of this and it will get easier. Here's a couple of resources I've found helpful:
https://brightspotsandlandmines.org/ Adam Brown is a type 1 and this book is 'what I wish someone had given me when I was first diagnosed'
https://www.dietdoctor.com/video/podcast#37 This is about low carb however I enjoyed it because he seems to get just how stressful type 1 is . I sent it to my husband when he told me that all I needed to do was test more!
Anyway, I believe you will get a lot from Dafne because everyone there will get it and share your frustrations. I am still going to the pub with the people I met there 12 + years ago!