From personal experience of trying not to eat when having high blood sugars, it just makes them worse. I've read this is because the liver starts chucking out glycogen cos it gets confused because you're getting no glucose from food.
I don't take insulin so things may be different for someone who does, but did run high for four days recently and, like you, kept trying to not eat in the hope it would help but it didn't... it was only by eating normally-ish again that they came back down - and then I learnt about the liver / glycogen thing and it made sense, so just passing on what I learnt in the hope it may help. Good luck and hope your numbers come down soon.