My T1D guitar buddy uses a pump, and he has been advised to only take intervention if his levels exceed 21 mmol/l or drop below 8 mmol/l. These are his in range values for his control and he has followed them for at least the last 15 years that we have been gigging together,
I am a T2D and not an insulin user, but whenever I was in hospital for repair, I too was subject to the same regime and was expected to only control between 8 and 15mmol/l anything outside this range was cause for concern by nursing staff. I am used to control between 4 and 8 outside of NHS land.so it was a shock for me. My current doctor wants me to be controlling to meet an HbA1c of 56 or above so again I differ in opinion as to what my control regime should be, It seems that the HCP's use a different set of values than us mere mortals.
So you may be expecting an unrealistic control regime of yourself and it may help your peace of mind if you can alter your personal goals to ones that are realisticsally achievable. Starving yourself is not going to help you in the longer term. and is not giving peace of mind and tranquility either.
There are several studies that show that insulin users using tight control of bgl levels actually had a shorter lifespan and or a lessened quality of life and it seems we can reduce bgl too low for natural bodily function. I am no expert, but there is evidence that you might benefit from a less tight control regime.