Caffeine increases stress levels so if your stress level has increased it may be that the 4 cups is pushing you too high and hence getting irritable. Therefore the answer is either to reduce the stress or reduce the coffee.
Another possibility is that you're hungry and need to eat more.
Amateur Doctor Assessment:
Caffeine increases stress levels so if your stress level has increased it may be that the 4 cups is pushing you too high and hence getting irritable. Therefore the answer is either to reduce the stress or reduce the coffee.
Another possibility is that you're hungry and need to eat more.