When do I count from?

I'm currently fasting 12 hours
then eat then fast 12 hours.
I also am on an insulin that
requires two injections a day-
Before breakfast and supper.
And I have to eat with each one.

Do I count the 12 hours starting
with each injection time
or each eating time?

My insulin needs at least
30 minutes before you eat
to start working.
So that means my eating is
not at the same time as the injection.

The other issue is that
I can't eat until at least noon.
And by midnight I'm usually
too tired or in bed.

I was on the modern insulins-
bolus and basal- but they
made me ravenous. The one
I'm on doesn't.
It works well for me.
So another insulin won't help.

Maybe force something tiny
In to eat early?