I've done various forms of low carb for about 12 years on an off, but my blood sugar is so much better when I am. My diet has morphed into something more like nutritional ketosis ala Phinney and Volek (shooting for <10 g carb/ 60 g protein and then whatever fat I need to be sated).
One thing I tend to do if I'm getting back on low carb and it's been a while is to undershoot a lot with my insulin for a couple of days and then bring it up as needed. You might want to do a very small amount of insulin before meals, like if you're fairly sensitive you might want to just try one unit, if not so sensitive maybe 2 or 2 1/2 and then test at 1, 2, and 3 hours post-prandial and adjust upward for next meal depending on how much higher than your target you were. I'm not terribly sensitive to insulin and I do 3 1/2 units for my afternoon meal (3 g carb, 24 g protein) and then for dinner I usually do 3 units (1-5 g carb, 30-35 g protein). For me, when I'm eating low carb, I don't even think in terms of I:C ratios because I'm eating so little carb that it doesn't make sense.
Another thing that might help in the transition is that you actually need to replace salt when you switch to low carb, maybe by as much as a couple of teaspoons a day. One nice way to do that is with chicken broth. I like to keep a pot of bone broth and have a mugful with a good bit of salt in it in the afternoon. It is shocking how satisfying it is (as apparently what I'm needing is salt, not so much calories). This can help you with the crappy feeling a lot of people get when their bodies are switching over from burning carbs to burning fat. When I switch over now, I almost don't feel it at all, which I think is part because I've learned the salt trick and partly because I think my body has just gotten better at it. At any rate, once you get past that crappy switch-over feeling, most people feel great and think it was totally worth it, so just remember it passes quickly if you do feel yucky.