I wish I could provide help, but I am on the insulin pump. All I can tell you is that in the last trimester my insulin needs tripled in all regards - food to insulin ratios and all of my basal rates. It is crazy how much the requirements change. You might just be hitting this part of pregnancy. I hope that you can find others who are on similar meds.
Good luck with it all. I have been T1 for 25 years, as well and am 30 years old and currently preggo with #2. My daughter is 7.5 months old and I am 13 weeks along with #2.
Feel free to write if you need to chat.