mark, trying to be serious here... i don't think you're overly sensitive at all. I think i'd be just as bothered by that myself.
what it boils down to is managing expectations. he shouldn't have waited for your initial assessment for 2.5 weeks, he did the right thing by getting you coming in as soon as possible.
his error lies in how he handled your expectations. he should've let you know right off the bat when you setup yesterday's appointment that he'd be gone for a week and checked if it was okay with you to schedule the next one (if there is a next one) for a few weeks later.
Instead, he slipped it into the end of a 90 minute session and consequently has caused you to question the entire process.
this doesn't mean he's not a good therapist, but it does mean that he didn't get a chance to learn all of the intricate things about customer service prior to becoming a therapist.
I think a good suggestion was made that you could pass the time by coming up with a bit of a game plan for your self. perhaps set some personal goals, and take the time to just figure out what you want out of the therapy.
It all sounded fairly positive up until that last bit, so I wouldn't let that stand in your way of a potentially good experience for you.
Wishing you all the best,