I’m getting so frustrated

So doctor said I had very high sugar in my blood (GD) and he started me on pills and that didn’t work so I’m on insulin injections (ouch) and I’m okay with that but it doesn’t seem to be working my levels are still super high!! Like has anyone had any experience with this kind of thing not a FTM but this is my first time on insulin I’m just so irritated because when I take it and eat my diet meal it’s still high!!

I have an appointment tomorrow but I just want to knw anyone’s experience!