Cancelled commission

So I cancelled that city commission on the grounds that the commissioner was unhappy with the quality and the speed of which I worked after only 3 days. I remained as civil as possible, whilst at the same time letting him know that he will probably encounter this scenario with anyone who he commissions.

"I’ve completed other pieces to deadlines that my commissioners have been more than pleased with despite me being in university. I did spend all day Saturday on your piece with which you weren’t happy. I have made every change that you have asked for, and that is why progress has been so slow. A completed sketch to the quality that I showed you cannot be achieved in 1 day, especially with such a complex composition and when so many changes were made to the very initial layout. Most professional artists would pride themselves in not rushing a piece and making sure it all worked well as a whole image, which could easily take a week or more to work through to a professional standard. This ensures that you would get the best possible art for your money.

I am sorry that you feel this way, but I do believe that it would best for you to find another artist if you are unhappy with my services. I have tried to make the image work for you, and obviously I am not the right artist for this piece.
Good luck with your novel and all the best with finding an artist that can give you what you require."

This experience has been a mix of emotions really; huge amounts of excitement at the beginning followed by disappointment and stress. As much as I would have liked to have worked through it, I don't think the commissioner was going to allow me that, as well as the time and artist freedom to create as strong a piece as I could for him.
This has been my first encounter with a difficult client, and I've learnt that I really need to learn not to take people to heart. The effect that this failed commission has had on me has been surprising; I felt sick every time I saw that an email had arrived from him, and dreaded working on the piece. I don't think a small amount of money and huge amount of stress were worth my making art seem miserable and totally un-enjoyable.

At the same time, I have learnt that not everyone will be as polite as I try to be, or will see a sketch in the same way as I do, especially if they have no artistic training. It's also proven to me that I am capable of staying professional and civil, even if that's not how I feel.

I now feel that I need to write up a short piece of information that I can give to any future commissioners to let them know what I expect of them in terms of ideas, detail, deadlines, etc. And in turn what they can expect of me and my prices. I need to also rethink my prices and what they include; at only £30, which isn't even minimum wage for a single day's work, I should make it clear that I would be only willing to do two revisions of the initial sketch, which in turn should ensure that the commissioner would give me the correct amount of details and information that I would need.