healthy pick-me-up drinks?!

I'm trying to find healthy drinks to increase alertness during the day. I'm stuck on 2 tea cups a day, and one diet coke in the afternoon. I'm trying to avoid caffeine though because I'm a stressed out person by nature, and need the alertness without the caffeine. Is this possible? Does tea have a lot of caffeine? Is coffee worse than tea? Also, is a diet sprite healthier than a diet coke? I heard soda melts your bones or something. One person suggested milk, a dab of tea, turmeric, and honey. Haven't tired it yet. I need some ideas please--calorie free of course :) Thanks.