I am currently a junior undergraduate student taking an Introductory Course on Probability Theory. I have been struggling with the subject for the last few weeks because mathematics can be challenging and I haven't built up enough intuition to train my mind to think probabilistically enough.
That being said, I'm between a few choices for a book for supplementary study. I've found the PDFs by Hoel, Port and Stone as well as Hossein-Pishro Nik's online text and Feller Volume 1. I was wondering, which of these books present the material in the most intuitive manner?
I often have a difficult time with Combinatorial Analysis as well, so I'm looking for a book that presents the material intuitively and yet rigorously enough so that I can truly gain a better understanding and grasp of the subject. I am open to any and all recommendations.