John,
Thanks for sharing your railroad odyssey with us. I have done the same thing in my own profession. I changed jobs to do something I had long dreamed of doing. Got there and found out that the price I had to pay for doing something I thought I would enjoy was just too high.
You checked it out, now you know you are capable of doing the job (Bob knew!), and most importantly, now you know that it just isn't for you. The important thing is that you recognized this early on and made the tough decision to move on. You WILL find some inner peace and I'm sure that the whole experience will be positively reflected in your artwork and how you deal with working on the narrow gauge.
Again, thanks,
Mark