You will get better with time. Like acidrock said, pizza is a huge challenge to dose for.
The best thing about what I have read so far is that you really do care about managing your blood sugar. That’s GREAT! It’s all to easy to just throw your hands up and ignore it. It’s a really good thing that you are making the best attempts that you can. Don’t worry about the kidney stuff, if you keep having good control of your BG the kidney stuff will be a long time off. Your A1C proves that you are really working to keep everything in check. Keep up the good work and keep posting on here, it’s great to have people to talk to.