I have had low blood sugar for many years. I could talk about it at great length but rather than launch into a TLDR, let me simply recommend this:
Try a rough approximation of the hypoglycemic diet and see if it helps. By that I mean first remove as much white sugar from your diet as you can (soda pop, candy, sugar laden breakfast foods, etc). Then have a snack about 10 am and another about 3:15 pm. A good morning snack would be a banana and a tablespoon of mixed nuts. For the afternoon snack, I recommend a slice of cheese and four triscuits. If you feel better after a week or two on this routine then its safe to conclude you have low blood sugar. And you can simply continue on.
I agree a doctor should be able to tell you more reliably but unfortunately they are not reliable when it comes to low blood sugar. Too many of them simply say if your blood sugar goes low eat some candy to boost it up. They don't realize doing so only compounds the problem.
That's the short version. I'll check back to see if there are any questions. Hope you feel better soon.
_________________
Your neurodiverse (Aspie) score: 120 of 200
Your neurotypical (non-autistic) score: 74 of 200
You are very likely neurodiverse (Aspie)
AQ = 38 MBTI = ISTJ Gender = Non-binary
I strive not to perseverate. You can PM me for more info.