Officially got diagnosed with T1diabetes. Treatment plan seems odd and Cigna won’t cover Lantus. Please help.

On Wednesday, I had an appointment in which I had my a1c tested. Thursday I was confirmed diabetic and was told they were placing an order for me to pick up at the pharmacy. I was supposed to have the medication on Friday for my follow up appointment. All the pharmacy gave me was the Verio blood glucose meter. At my appointment, the nurse said my treatment plan was to take 6 units of Lantus every day. Which, after speaking to my diabetic siblings seemed like a low amount. My A1C was a 9.6 reading which seems to be pretty high. They’re not having me take insulin around meals either right now. But, they said they’d call the pharmacy and get it squared away so I could pick it up by Monday. That’s fine. Today, Saturday, I receive an automated call from my insurance that says they’re not covering the Lantus. They also told me I could call and try to appeal it but it’s Saturday and their offices are closed. So I can’t do that. What am I supposed to do about this?

Side question: When I told my dad about my diagnosis, he lectured me and told me that had I been eating better and healthier, this wouldn’t have happened. Essentially, I should have taken heed from when my siblings were diagnosed and changed my entire diet so that way there wouldn’t be a chance I could get it. It’s weird to m because he’s a T1 diabetic too. And also, he’s a medical professional and has been for years. My understanding is that T1 is genetic and either you get it or you don’t. What causes it still isn’t known. It seems like a genetic lottery thing to me. Is he right?