I think I am in a similar situation, but I didn't get a c-peptide test done, so can't be 100% sure, but my official diagnosis is that I am Type 2. I was on metformin for three years and then moved to a Basal/Bolus insulin just over two years ago.
You don't mention what type of insulin you would be moving to, so if it is to a basal only regime then very little of what follows will apply.
One thing I have learnt about diabetes is that everyone is different in some way, so your experience with insulin might be completely different from mine.
Dis-advantages I found to using Basal/Bolus insulin.
- I have to be more careful and when I eat otherwise I risk going low.
- I have to inject before every meal.
- I need to monitor my levels more to make sure I don't go low or high.
- I need to know the carb content of everything I eat.
Advantages I found
- It gives me more freedom in what I can eat (Although in practice that does not seem to matter much to me)
- It works!
So in the end, it is the only last one that matters. Metformin stopped working for me, and insulin does work, so I'm happy to take it.
Re low-carbs - When I was first diagnosed I was underweight, and when I was switched to insulin even more so, so I wasn't on a low carb diet at that stage. My carb content is now around 100 per day, which I think is technically low-carb, but still considered a lot by the ultra-low carb followers. (I am aware that it is ironic that my carb content is lower now that I am on insulin than when I was on metformin). I did try lowing my carb content even further, but found that I still needed insulin even for a 4-carb meal and I started to loose weight again, so I went back to the 100-a-day level.
The other thing I that I found helped me enormously was the free-style libre which I have been using for about 15 months.