There is not much guidance to give apart from what you already posted, namely,  to release any fear and simply let it be. 

What is occurring is during sleep; where the intellectual facility appears to be half asleep and half awake; is possible & ordinary. For example, I have experienced real wisdom engaging during dreams (generally about death); where wisdom engages and reflects: "*This is only a dream*". 

As for the sensations, this is just mental formations moving around & arising to purify (what you call: "*humming flow of energy flowing*"). Again, there is not much guidance to give apart from what you already posted, namely,  to release any fear and simply let it be. 

Often, when my body-mind have releases of energy during sleep, the mind has dreams of literally flying in the sky; over oceans & cities at night; which is extremely enjoyable & refreshing. The mind can do these things because this is the creative or imaginative nature of the mind; that is all.  

Also, the Buddhist scriptures mention supernormal mental occurrences, such as visions and perception of external events (called 'Divine Eye' & 'Divine Ear'). All of these things are mere possible mental happenings; that require release of any fear and simply let it be.   

The core teaching of Buddhism is "*non-attachment*" towards all experience. 

> *When a monk has heard that nothing is worth clinging to, he directly knows everything; having directly known everything, he fully
> understands everything; having directly known everything, he fully
> understood everything, whatever feeling he feels, whether pleasant or
> painful or neither pleasant or painful, he abides contemplating
> (observing) impermanence in those feelings, contemplating (observing)
> fading away, contemplating (observing) cessation, contemplating
> (observing) relinquishment (letting go). Contemplating (observing)
> thus, he does not cling (obsess about) to anything in the world.*
>
><a href="https://www.dhammatalks.net/Books9/Bhikkhu_Bodhi_Culatanhasankhaya_Sutta.htm">*Shorter Discourse on the Destruction of Craving*</a>