and had to go back to drinking soda because of the headaches.

It's most likely from not having enough sleep. Usually lack of sleep correlates with consumption of caffeine(no shit, Sherlock), but caffeine is usually not root cause for it. Usually it is external source of stress like school.

I've seen far too many lives get ruined through addiction. In fact, one of my life goals is to volunteer at a charity to help people kick addiction to consumerism (I'd love to help people get out of debt).

Good human. No, good citizen.