Hi Kiki,
Tea does have a lot less caffeine than coffee usually, but it all depends on how much you use and how long you steep it. Also, some people's bodies are just sensitive to caffeine and it doesn't take much to keep you wired at night. Do you happen to like any herbal teas? That might be a good sub. I actually like drinking hot water with just lemon. Very soothing to me.

I was thinking also that insomnia could be caused by blood sugar problems. This will even out as you go through your steps.

Vitamin waters are loaded with sugars, so if you haven't tried them yet, I think it's best not to get hooked on them.

Dodi