This sounds like a really painful situation!

Hopefully this doesn't come across as harsh, but I do feel like you may need to adjust your expectations or find a therapist who isn't so busy.

You said your therapist is missing his receptionist, so he is handling all the administrative work of his practice alone. This could be an enormous burden. You didn't mention whether or not he takes insurance, but I've heard that working with insurance carriers can suck hours out of a work day. Also twelve hour days are incredibly tiring.

What all this means is that your therapist is being pulled in many directions and has to triage all of his clients. Essentially responding first to any suicidal clients, then to those in truly desperate conditions. To get attention, I'm guessing you'd have to be in pretty bad shape.

I'm not trying to take your therapist's side at all. I don't think a therapist strained this way can be of any use to a client who requires some outside of session support. Nor do I think he can be entirely checked in during all sessions. I'd look at the big picture - if generally he has been great and this is just a difficult time for him, you may need to be patient until the situation resolves. Otherwise, you may need to find a therapist with a little more time and resources.