Schrodinger's Diabetes! It both exists, and doesn't exist, until you confirm it!
In all seriousness, take care of yourself, please. If a one-time, fasting lab test can either alleviate your fears or get you help before it becomes an even bigger issue, then I'd suggest talking to doctor about those tests. I know, at least if you're in the US, the healthcare system sucks, and you might not have insurance to afford a full battery of tests, I'm not shaming. I get why you may not have seen a doctor or gotten tested before now. However, we (human people) are not around long enough to spend part of it in fear of something and the another part of it in pain treating the thing that we were initially fearing.
I'm rooting for you!