I'll ask about all possibilities. She actually looked at my LibreView this morning and reckons that such a sudden and steep drop is unusual and maybe the previous reading on the Libre was incorrect (I.e. I was already low). Also she noticed that I had "stacked" (I think that's the word she used) my novorapid doses at 5PM and 8PM and that I had barely any carbs for dinner (at 8 PM) -- may as well say no carbs, it was the filling out of two meat pies and I logged it as 5 g which was a guess but seems reasonable... I didn't eat the pastry casingHope you are feeling better this morning @plantae . I have no idea what is causing your hypos but I strongly urge you to push for your DN to consider all possibilities.
If that means you need to change to a different basal, a different cgm or even a pump, so be it. (Not a recommendation to do any of those, just a sample of some of many possible changes that could be made). Is it safe to assume that you are under an endocrinologist that is experienced with T3C???