>>2585374Try communicating your concern, being blunt while still being polite.
"Hello,
I hope you're well. I'd like to ask about my commissions - I commissioned you on (date) for (things). Could I have an estimate of when they will be done?"
If you feel like being more firm, add:
"I've noticed you've gotten some other, recent commissions done. I understand you are pressed for money, but I have been waiting for longer. I expect you understand why this is a problem."
If you're worried about their anxiety, simply point it out:
"I understand this might make you feel nervous, but if you communicate clearly what is happening, I will be happy."
Yes, even if you're not, but you get more flies with honey than vinegar, and this way you don't risk sending the artist into an episode of full on anxiety.