is there just 'one' light?

[Tenet Nosce]

question is: is there only this 'one' Light?

Yes.

we ourselves tap into this one light

You are not speaking of similar or somewhat like entities or things. You are every thing, every being, every emotion, every event, every situation. You are unity. You are infinity. You are love/light, light/love. You are. This is the Law of One.

So, to continue.

We know there is one light. We also know that it is streaming from (at least) three different locations.

One location is the earth itself, which appears fixed relative to the body.. This light is gathered in the feet and travels up the lower extremities into the base of the spine.

The second location is the body itself. This source is internal to the body, and we also know that it moves relative to it.

The third location is the sun itself. This source is again external to the body, and appears to move relative the body.

What else do we know about light? We know that it has (at least) two manifestations: a particle and a wave. A particle is the physical component of light, and a wave is the metaphysical component.

The light emanating from the sun and the earth is in physical form. The light emanating at the inner "mobile" location is metaphysical in nature.

Ultimately, it is all the same light. The only difference is in the paths that the light has taken to arrive at the Present Moment, and whether the light arrives with or without its physical form (the photon).