*tightly* You're welcome. *deep breath, calm down* Start with one animal into another, like we discussed earlier, and when you can do that correctly and reliably, you'll need to do it without your wand.
*stands up, and steps behind his chair as he pushes back into place* And if you have any questions about the transformation after that... *small smile, because he anticipates that Q likely will have more questions* ...we can discuss those then. *is polite, but the smile is strained, and there is an undertone of "we can discuss the Animagus transformation and only the Animagus transformation"*
Oh no, don't apologise -- either for you or Q!
For Sirius, it's the perfect storm of (i) having had a recent, similarly frustrating with Sev (frustrating for different reasons), (ii) trying to explain things/teach -- which, even under ordinary circumstances, he really, really doesn't have the patience for, (iii) dealing with someone who might be ill and wants to be helped, but doesn't want to be diagnosed or listen to anything Sirius says, and (iv) Voldemort :\ The mention of Harry was kind of the last straw.
Sirius will definitely still help Q with Animagus (if Q still wants it, after this!) but unless Q wants/you want Q to be diagnosed, might be best not to bring V into the conversation again?