I've been diabetic for 30 years. And it was only a few years ago I discovered that simply by eating rye bread steadily throughout most of the day, my blood sugar tends to stay stable for 24 hours. (Though of course I must keep an eye on things: I test around 16 times per day, mostly using visually read strips.) I don't eat any after 4.00pm, for this would make me go high later in the evening and overnight.
I eat other stuff too, of course. And I eat very well indeed.
I don't take any significant amount of long-acting - so called 'basal' - insulin: just a tiny amount last thing at night to stop the blood sugar rising overnight. This means that I always go to bed without fretting whether I've eaten enough.
Before I got onto the rye bread, I was regularly having hypos, and my blood sugar would constantly yo-yo.
Now my blood sugar tends to be near normal all the time. (And it's so simple; I don't have to 'count carbs'.) Moreover I have no great fear of hypos.
You've said your diet doesn't change. You could try changing it, carefully.
I've just had a look at your other recent postings. And I see that you may have some kind of infection or something. As others have said, this would certainly make your blood sugar rise.
In my case, an extra bit of Novorapid injected into my stomach area - as opposed to anywhere else - brings the level down very quickly. (So be careful!) Personally, I would never take extra injections of the long-acting insulin.
