Reddit reviews Isis Unveiled: Both Volumes - A Master-Key to the Mysteries of Ancient and Modern Science and Theology (Illustrated)

I recommended the Kybalion in my previous comment before seeing this post. It seems you have already read the Kybalion then. You are already off to a great start. But there are, as always, up to seven layers of meaning to any text. So you should consider it as more of a reference work than anything; only when your journey is complete will you be able to make full use of its contents.

I might have also referenced the Bhagavad Gita. It seems like our attraction to the mystical is in a very similar pattern. Since you have gone this far, then, as per my other comment I would recommend Mark Stavish's Egregores, but also I might recommend the works of Manly P. Hall, and also his largest influencer, H. P. Blavatsky. Specifically ISIS Unveiled for the latter.

Manly P. Hall would be an especially good resource for so-called "fast tracking." His works are very encyclopedic. Particularly his masterwork The Secret Teachings of All Ages.

You may also find Max Heindel's The Rosicrucian Cosmo-Conception beneficial.