I too have quit coffee and switched to green tea, which I will also slowly quit.
For a while, I went on insane caffeine binges, while pulling all nighters and trying to get a lot of work done.
After that I was exhausted for weeks. My adrenaline glands probably were burnt out completely and I felt drained and my energy levels and mood were swinging all over the place.
Caffeine is a vicious circle. You drink it and you experience positive effects, that you want to experience again and again, but it also makes you sleep less well, and the next day you drink it purely to get energy. You become a slave to it, like with any other drug.
Also I started noticing I have weird burning sensations in my chest (probably also an anxiety sympton) that come with troubled breathing.
Last but not least, I feel like when I'm on coffee, I'm not completely in touch with myself and my thoughts/intuition. I am quickly distracted, and the stuff I produce is robotic and un-genuine. Conclusion: I need to rely on exercise instead to get the endorphines flowing, and to get more energetic.
I started drinking soda's from a very young age and was introduced to coffee at the age of 17. I sometimes ask myself the question how my overall anxiety and energy problems would be if I never started poisoning my body with these things. One can only wonder.