Change instructor or school, I'd say.
Many instructors are simply not very good at teaching - it's not an easy job and it requires a certain enthusiasm or personality to imbue knowledge in an effortless way and in a way that has the student really absorbing it. Just think back to your school years - there was always that one teacher that everyone liked and learned a lot from. But they're rare - there was never more than one, if even that.
It can be extremely depressing when you sense you're not making any progress. I've recently had the same experience doing my FAA standalone license and I changed instructor.