updated by @emmy-long: 04/02/17 06:30:27AM
It depends on the source of the caffeine for me. Coffee is a straight upper - it makes me calm and happy. Cola drinks make me nervous, anxious, panicky, and jittery. Chocolate - which has a chemical similar to caffeine - makes me really angry, depressed, and gives me bad dreams. When I eat chocolate I start hitting walls and breaking things and screaming for no reason.
If you can't drink caffeine but need something to give you energy, try some liquid Vitamin C. I take that every day and it energizes me. It usually comes in an orange flavor. Make sure you're drinking enough water, too.