Kate,
first of all, yes, I'd look around for another oncologist. He definitely should have had access to his oncologist through all of this. I suggest you talk directly to the oncologist and tell him all of this. In fact, print out this post and take it to him. He may not realize what's going on in his office and that patients are not being given access to him.
Second, Dave is taking cisplatin and he gets a prescription drug called Emend to take for nausea while getting the cisplatin. It's a pill, you take it the morning of chemo and one the next day and the third day. It's VERY expensive, like $100/pill but his prescription drug coverage gets it down to $40 for the prescription. It really works wonders it seems.
Stay on top of things like you are. You are doing a great job being his advocate. And yes, I would NEVER settle for waiting for any test like a MRI or MRI saying someone wasn't available is BS. I would go to the ER if the regular doctor's office couldn't get it scheduled ASAP.
I really feel for J, he is going through alot of physical stress. Hang in there and please keep us posted on how he's doing and what else they find out about him.
Karen