IF and exhaustive afternoons

Workout 5:30-6:30.
Caffeine water until 11:30
Eat lunch which is usually meat, rice, veggie sometimes fast food
Caffeine water until 2:30
Dragging arse 1:30-4
Eat dinner at 5:30
Energy levels fine until 9:00 bed time

Thinking it’s some low sugar issues which is why I used to pass out after 3:00 workouts

What should I tweak??