Hi there and welcome!
Sorry to hear that you are feeling angry and upset. It is quite a natural thing to feel as you are feeling. Don't despair, it WILL get easier. I am sure that most of us on this site have had feelings that are similar to yours. Also, again, our blood sugars do fluctuate, sometimes a little high, and sometimes a little low! It's just getting the right balance re insulin and food consumption.
It's very early days for you, and naturally your feelings are like a rollercoaster, but hopefully once your BGs settle down, it will be better for you. The last few days have been difficult for me, re BGs, I have had a couple of hypos today, 2.8 and 3.1, however, although it's annoying, I know I'll get back to a respectable level. I know because of experience. I realise that you have not at the moment got the experience, BUT, that is why this message board is invaluable, just by reading the different posts will enlighten you to different situations and opinions that other diabetics are experiencing. I know that before I came on this forum,, I thought that I was the only diabetic that could not get my levels right!!! Also some threads really make me smile. So again, welcome!