Sounds like you had some of the worst instructors available. If the OP instructor's is as unapproachable as that, I would certainly recommend changing schools.
I always try to be as open to questions as possible. Usually after ex4, or possibly after ex6, I just sit in the aircraft with the student and ask them if there's anything they're not sure of and want me to explain, be it the suction gauge, the alternate static source, anything that I may not have already explained in full. I try to keep this going throughout the course, and any specific questions I would then refer them to the relevant section of the POH to build their familiarity with this document. It also builds in the student the attitude that there are no stupid questions, so they won't be too shy to clarify something that they think might be deemed obvious.
Perhaps I assume this is how all instructors go about their trade, but if the OP is getting less than this for his money he should certainly be talking to the school about it.