If you have low levels of insulin you might have trouble getting that glucose where it needs to go. If there’s nothing wrong with the production of insulin as such it might be over suppressed. There’s a hormone responsible for suppressing insuline connected to the stomach, forgot what its called, but it’s known that gastric bypass patients can have trouble with this. There is thing called “dumping” which they experience, similar to an anxiety attack, connected to this. Might be an area to look into.