If I were you I’d cut out the brown rice.
When I did this, my symptoms stopped.
Your body will adjust to a low carb diet eventually, and you will have no blood sugar drops if you eat no carbs (and no caffeine).
It is the brown rice giving you blood sugar swings. It can only be carbs (or stimulants) that give you swings, so it must be the rice.
Eat more eggs, etc.
When I need extra energy, I eats nuts and I am fine (it is better to soak them first to kill mould). Some people, however, get symptoms when they eat nuts.