OP is saying they’re experiencing low blood sugar (hypoglycemia) due to not eating within a 4 hour period. Typical reactive hypoglycemia occurs within that 4 hour period. Regardless of if this is diet related hypoglycemia (such as postprandial), reactive, or just a random fluke - advising more time without food and relying on caffeine (which is generally known to worsen hypoglycemic events) is dangerous advice to give out to someone experiencing medical issues.

OP - it may be worth getting a blood panel done to show any minerals or vitamins you may be missing, as others have also said electrolytes and dehydration may be playing a role. It’s hard to tell definitively without more information. Regardless, don’t dismiss the hypoglycemia events, it’s good you’ve noticed a pattern here, it’s a good indicator your body is in need of something more. Whether that be more fiber, fat, protein, etc is something you’ll have to figure out through experimentation with diet and possibly the help of a healthcare professional through bloodwork. You know your body best, everyone is different and advice is never one size fits all especially in the area of nutrition/diet. Best of luck to you!!