Not advice from anyone, but the best thing I realised soon after diagnosis was that as the diabetes team I first encountered were no use to me - I don't think they knew what to say to an active 30 year old with main aims in life that didn't involve having children, not least because I didn't have a partner then - was to "trust my own instincts".
Gradually, over the years, I met friends, colleagues, health professional who I could trust - and many confirmed my initial instincts to live as active and interesting life as possible. Which includes sensible testing, injecting, eating, activity etc.