Welcome to the forums.
Are you T1 or T2? MODY?
Different people need different amounts of insulin so 20 units could well not be enough.
1) First question, have you talked to your clinic about this? You definitely need some help
2) How confident are you that your basal (the tresiba) is correct?
3) When are you getting the high readings in relation to your evening meal and novorapid?
4) What are your readings like at other times of the day/night.
Some thoughts
1) you're injecting in bad spots and the novorapid is not being absorbed properly.
2) Is your novorapid OK at other times of the day? Last time my sugars went crazy I discovered there was a crack in the cartridge of my fast acting insulin and very little was going through to me when I injected.
3) Could your novorapid have gone off?
But 30 is way too high - you should not hesitate to ask for help. We can make some suggestions here but it's really hard to know what is happening when we don't know your medical history. Your team should help you.
Good luck. Most of us have been depressed by diabetes at one time another. This forum is a safe space to express your unhappiness, get some moral support, and hopefully give you some suggestions as to what you can ask your diabetic team.