"Just eat less" is not a very helpful answer, it's incredibly frustrating to hear, believe me.
When your blood sugar is in the 60s or 50s range from trying like hell to do your diet all day, reason goes out the window and 'mere' will power is not enough.
It takes a lot of effort, lots of planning (preparing food, planning what, where and when to eat, snacks, etc) and a LOT of information (nutrition, insulin effects on the body, pros and cons of current 'fad' diets, etc) which takes a while to collect, also, lots of trial an error.
It doesn't help that most doctors, are clueless regarding healthy eating.