Your instructor was not doing his job in the best manner possible. No
harm in flying in conditions way above the student's head but an
introduction to the "wild side" must stay within the student's comfort
zone as this is the only condition in which learning can occur. He
"owed" you a pre-briefing as to what you should expect in this
environment, and an explicit discussion about terminating the flight
should you feel the need.

It is the instructor's duty to discern the student's emotional
condition, abilities, and experience levels and ensure that he is able
to learn. Note that your education is only goal of the flight! The
instructor's natural desire to have fun in the ripping conditions is
unimportant and in this case, counterproductive to your progress. I
would submit that the instructor failed his duties in this particular
instance in not recognizing your emotional state and by not being
proactive in ensuring your mental/emotional comfort. The CFI whose
student became airsick really blew it. In both instances, the student
learned "negative lessons" - that flying makes them afraid and/or
airsick. As you have already recognized, these are steps backward in
learning to fly.

Fear is a common and reasonable behavior when confronted by
circumstances beyond your control and experience. Acknowledge that
fact and move on. As part of that analysis, I would seriously evaluate
the instructors available to you and select one based on their
commitment to your needs as a student needs and their obligations as a
teacher.