It's all done on the fly.
My daughter is 19 m/old now, and was BFed until she was 8 m/old, until the teeth lol.
I went from 22/day of Lantus &16 of Novorapid at the start, up to 32/Lants and 28/Novorapid during late pregnancy.
While I was breastfeeding mfor the first month at least it was do what I can when I can.
It varied so much each day.
I had an emergency c-section at 36 weeks, so that probably didn't help my recovery lol.
Eat what and when you can. sleep comes first though. After abot a month I stabilised out again, and have been progressively lowering it as my baby weight has come off.
It's now pretty much what it was before, 24u/Lantus & Novo as needed.
A lot of low-carb snacks are good, so if you get hungry just after a meal you don't have to worry about dose overlap etc.
It will be different for everyone. Enjoy yoursef, congratulations, and you sound like you are doing great