I really appreciate your answer because it helps put a lot of the details in focus! The consulting time is definitely something I overlooked, as well as making changes. I got lucky this time with a pretty flexible and easy to please customer, but next time might not be the case!!
This started out as a hobby, but I've been considering trying to make it more of a job. That was partly why I offered customs, thinking it would mean more business--and it does, but I just don't have the luxury of enough time to do it properly without being overworked like your friend. I'm concluding that it's not a realistic job at this stage of my life :)
Once this last customer leaves a review I'm going to remove that listing and then just write a blurb on my main shop page saying to message me about custom stuff. Then I can accept or turn down work on a case by case basis. There's just too much pressure once the customer has already ordered and paid. At least this was a decent learning experience ;)
Thanks so much!!