Spin… It’s one of those topics that can drive anyone crazy. It all makes sense in the mathematical formalism, but unless someone has a spontaneously abstract mind (think Dirac) it doesn’t help for most of us to ‘understand’ what spin is.
Rather than textbooks, Youtube is the place to be for good explanations at this level. Here are a few video’s that may help to construct a mental picture that is physically justified yet not abstractly mathematical: