I too was age 27 yrs old when I was dx T1, but that was 47 yrs ago, so I've been at it quite some time now In 1969 when I was dx everything was very basic, with just one Lente insulin injection in the morning and remember to eat at regular intervals or else I could be in trouble. Anyway I was dx during a medical check-up, incl urine test, for a new job that I was just about to start, but had not experienced any extreme symptoms (thirst, going to toilet, weight or tireness) so I guess it had not progressed to that stage for me. So the possible trigger was a combination of new job, new location and due to get married in 6 mths time, but you can never be sure.
So it was straight onto insulin, with no hospitalisation etc ... in at the deep end whilst living on my own in temporary accommodation. But once living with my new wife 6 mths later, she was very supportive and we learnt as much as possible from the odd leaflet handed out. I was told to eat 140g carbs/day made up of x3 meals of 40g, plus x2 snacks of 10g. So I basically stuck to that for the next 40+ yrs, and although control was variable at times, once A1c testing was introduced in 1980s, it was much easier to see how I was doing. I have records of all A1c readings in last 16 yrs, since 1999, and I was in the 7.5% to 8.5% region for many years, with hypos in early mornings quite often, for some unknown reason, but no complications developed as that control level was acceptable ... just.
Anyway, about 4 yrs ago I decided to check out online support groups and learnt SO MUCH that I had no idea about before, such as MDI basal/bolus regimes, insulin-carb ratios & correction factors. So I decided to take all this new information on board and taught myself carb counting & bolus adjust based on ratios, and since then I've recorded a steady reduction in A1c from ~7.5%, to 6.9%, to 6.5%, to 6.3%, and last one since using Dexcom CGM in last 4 mths, I broke my record with 6.1% (43) with no more hypos also.
So that shows what you can achieve by educating yourself on all aspects of T1 self-management, which is what I would strongly recommend, and also take on board the latest technology where possible.
Best of luck ... Jon (UK)