Hi
@sarahjb
I'm having the same problem right now so you're not alone. If you also read the thread Type '1 Stars R Us, I was given lots of support there and I think it would help you.
I've only had T1 for 2 yrs so I'm just learning.
The main thing about this steroid injection I've found, just like you, that BG is much higher than I've ever experienced and that I'm having to inject far more bolus and have increased basal too. As
@helensaramay says, insulin resistance and I don't know what happens about this after the steroid has dissipated.
Anyway, don't worry. It's just what happens, put it down as a T1 learning curve. We'll be OK in a couple more days