Hi,
@TIGERLILY1991 , fixed doses are fairly standard with newly dx'd as it reduces the amount of variables involved and makes it easier for the docs to figure out ratios.
It won't last forever, so I'd recommend going with the flow for now - there'll be plenty of time for figuring out your own techniques once they let you off the reins, although I do agree with the other posters that this should really only be a few weeks or a month or two.
Another acronym to get familiar with is CGM, continuous glucose monitoring. A small device gets stuck on your arm or stomach and sends bg readings to your phone every 5 mins, so you can track how bg is moving. It makes managing bg levels several hundred percent easier when you can actually see how those levels are moving.
One thing to be aware of is that there are dozens of variables involved, which is why x units of insulin for y grams of carbs won't necessarily work out the same way two days running.
That can lead to newly dx'd becoming hugely frustrated - they're playing by the rules, but T1 isn't.
There are no quick and easy answers to this. Sometimes T1 is just plain unpredictable. With time, though, and cgm, you'll figure out plenty of techniques to even out the randomness.
Stephen Ponder's book, Sugar Surfing, is a good read on both using cgm well and psychologically accepting that we are dealing with a moving situation.
Unlike other conditions, which basically involve taking a pill or two each day, T1 involves active management where the patient makes the decision. Ponder's book is good at getting the point across that we can actively steer and influence the direction of our bg.
I've found it helps to not think of T1 as a threat or enemy. I think of it more as a small child which needs to be looked after - sometimes T1 behaves, sometimes it doesn't, but whatever it's doing, you're always going to look after it.
Good luck!