Wow Vik!!! That's an incredibly exciting and busy life -- I guess you squeeze in sleeping and eating with the few hours that are left! ;-)
Kidding -- you do a magnificent job!
You asked -- how long do I spend on Medium, HOURS!!! I would say I spend at least 4-6 hours a day. This is my third month and the first time I have ever decided to write. I love it and I will work on a draft for days; but I spend a lot of time reading and engaging with my followers. I would say most days 70% of the time is reading and commenting. Some days like today -- has been 90% writing.
I've been editing a draft of mine--- and it's in these hours that I learn the most. I don't rush it, it's my process and truth is if I were to actualize the money I'm making for the hours I'm spending it would be less than a cent.
However, I'm at the beginning of the exponential curve. I trust the process -- and as you well know, once you allow time to take over in exponential growth -- I will reap great rewards!
I look forward to reading your journey -- thanks for shaing all that you do! It's inspiring!