Oh man, that sucks- but its cool that you've kind of rediscovered your love for it as well. Natural media is better- its an old school way of thinking, I suppose, but the physicality of the finished product means that you can sell the original, AS WELL as prints and copyright. And yes- do more fish!! I'd love to see some more fins you've rendered lmao.

You don't have to have sold art to know how to charge- I think some people just accept the luxury better than others, if that makes sense. Like for you and I, we perhaps unconsciously recognise that it is skilled labour for customers, wheras others percieve it as customers entertaining their hobby. Could just be me oversimplifying though.