PChem is not really all that difficult conceptually, when you consider the mathematics behind it at the same time you look over what's being presented. Too many students go into PChem studying it like they would any other course, and perhaps that's why it's gained a reputation as "the most difficult undergraduate course anywhere." PChem is a MATH course, not really a Chemistry course. Study it like you would any math course (by understanding it mathematically and practicing the math on your own).
If you're a math person, all the more power to you. If you're not, seek some help in understanding the math first and then all that junk will fall into place.
What level of math are you?
Tim of New York City.