I think the coffee supply of the world will become a lot smaller on my account

Coffee IS the magic word. It can fix deals, move the mountains or my ass.

Dont doubt yourself . before u notice, some creepy little talking obstacles will appear around you...just do your thang sista

Are there any official schools or academies for tattoo?

To get this topic back on track:
I started my career change couple of years ago, at first I started drawing tattoo designs and selling them on Etsy. It went weary well. Soon I started my own business (beside the full time job) of making customized tattoo designs. Now I'm here on Althemy and slowly thinking about opening the website to do the same. For my next step: I started apprenticeship two-three times a week for a couple of hours after work to become a tattoo artist.
Career change is often difficult and time consuming, strength devouring and tiresome. But if you really love what you want to do, and have real passion, doing two jobs, learning whole new set of skills, lack of social life or family, all while making a name for yourself.... It will be worth it at the end...