IMHO, possibly the best book written on this subject is "Practical Psychic Self Defense" by Robert Bruce. Most the recommendations practical, physical things you can do in 3D.
The author also wrote Astral Dynamics... probably the best systematic and guide to astral projection and the structure of the astral realms. Individuals with their first astral projections often encounter a "Dweller on the Threshold" experience with an evil entity tries to scare and deter them from their goals.
All I can say is that you have probably amassed a large amount of light by your workings; and negative entities wish to eliminate that potential by playing into your biases, dare I say an excessively empirical (scientific) mindset and desire for proof. As intellectualism is your approach, consider the rationalist critiques of empiricism such as the problem of induction. In fact, the very existence of Mathematics, grounded epistemologically in rationalism, and an "A priori", deductive approach, is anathema to Empiricism. Since the natural sciences are grounded epistemologically in empiricism, this clearly shows the limit of this approach.
As for guides and entities... Yes, Edgar Cayce didn't need them. All is available directly in the great record of creation, the Akasha.
Edit: You sound like you might need it fast. You can get the book on Kindle Edition and then read it on your desktop if you don't have a kindle.
The author also wrote Astral Dynamics... probably the best systematic and guide to astral projection and the structure of the astral realms. Individuals with their first astral projections often encounter a "Dweller on the Threshold" experience with an evil entity tries to scare and deter them from their goals.
All I can say is that you have probably amassed a large amount of light by your workings; and negative entities wish to eliminate that potential by playing into your biases, dare I say an excessively empirical (scientific) mindset and desire for proof. As intellectualism is your approach, consider the rationalist critiques of empiricism such as the problem of induction. In fact, the very existence of Mathematics, grounded epistemologically in rationalism, and an "A priori", deductive approach, is anathema to Empiricism. Since the natural sciences are grounded epistemologically in empiricism, this clearly shows the limit of this approach.
As for guides and entities... Yes, Edgar Cayce didn't need them. All is available directly in the great record of creation, the Akasha.
Edit: You sound like you might need it fast. You can get the book on Kindle Edition and then read it on your desktop if you don't have a kindle.