My diagnosis was shocking too as no one in my family has it and it was just really odd and I never expected it, I went in the ER with bad GERD/acid reflux (kinda worried I was having a heart attack or something like that it was THAT BAD lol. Though now I wonder if it was my pancreas instead) found out I had diabetes in the process and in the end it made sense as I had some weird stuff going on recently (like peeing all of the time ,stomach upset that was likely related to high blood sugar, being thirsty a lot, etc...but of course I didn't know I was symptomatic until later on, but still important). I completely understand being upset too when your treatment doesn't work as I went through the same crap with Metformin , though they never put me on anything else until I started insulin (and was taken off the metformin) . I was constantly above 200 on metformin unless I ate nothing for like an entire day (which was honestly close to what I did I was starving myself due to the whole type 2=fat people disease shame people directed towards me) . My A1C has never been all that high , but I wasn't immediately tested for my a1c so I have no idea what it was at diagnosis, but after a few months I was 7.2% , insulin brought me down to 5.5%.
I'd say on the whole pizza thing though? Pizza effect due to the fat in pizza, that makes the carbs hit your system very slowly and leads to it not hitting you until like 4-6+ hours. I had to be careful with fat at first, but now that I'm pretty sure I'm honeymooning (meaning my last few beta cells have not kicked the bucket yet and are trying to help me out) , it's less of an issue.