You really have had a tough time. I'm so sorry for your loss.
DS1 is 3.5yo, and I bf him for 3 years.
DS2 is 10 weeks old, and I was diagnosed with gestational diabetes at about 34 weeks. It was the final straw for me after a difficult pregnancy, and I worried a lot.
I was due to be induced at 38+2, but the consultant was not concerned by any risk of waiting. DS2 was a healthy weight, numerous scans showed everything was as it should be, and she told me that there was no real risk if I waited until 39 weeks (for example) as my numbers were not particuarly high (even though I was on medication), and everything else was as it should be. I chose the induction date to fit around childcare, as DH and I are a long way from family.
As it happened, I went into labour a few hours before I was due to go to the hospital, which wasn't entirely unexpected as DS1 (9lbs 1oz at birth) had been born at almost the same gestation. Interestingly, my levels dropped to normal the day before, which also made me wonder if things were about to start.
DS2 was born at 9lbs 3oz, and I bf him almost immediately. He was handed to me straight after he was born, I had a cuddle, DH had a cuddle, the midwife did some checks, then he was handed back to me and I fed him. They then did the newborn tests. His glucose levels weren't checked until later, partly because he seemed happy to breastfeed I think.
When his levels were checked, they turned out to be very low, and the doctors wanted to top up his feeds immediatly. This was the last thing that I had wanted, but as his levels were so low it felt more like they were giving him medicine, if that makes sense. They were supportive of my desire to breastfeed, but I also just wanted them to do what was needed to raise DS's levels. They showed DH and I how to cupfeed. I asked to see the infant feeding coordinator (she was great), and she showed me how to express and collect colostrum. DS stayed with me during my hospital stay.
The use of formula, even under these circumstances, did make me wobble though; I felt less confident in my ability to successfully breastfeed. I was glad I had been given the chance to bf him first, but I just worried that I wouldn't be able to feed him properly myself, particuarly as his low blood sugar was making him very sleepy. As soon as his levels rose they stopped the top ups, and as DS was less sleepy he bf well.
I didn't worry about any risk in neonatal period. Even when his levels dropped, he seemed healthy and it felt as the the doctors had it under control (if that makes sense). There was no panic, and once they had stabilised I instinctively felt that he was okay. I can understand why you would worry though. Even though I haven't had the same past experience as you, I worried myself sick towards the end of the pregnancy.
I know this is a huge post, I just tried to cover everything.
Wishing you all the best. x