Hi dronjom,
You are facing an interesting question for sure.
I wouldn't like my way of life interfering too much with your beliefs or the way you conceptualise the world we are evolving in.
I am tempted to say that you experience musical creation in its most immediate way. By singing, by following and reproducing a movement that come from within. As it is a vocal creation, vowels and consonances will commonly appear as these are the tools we have to sculpt the sound using our breath, tongue, mouth, throat etc...
It reminds me of the chant that a shaman could produce for example, altough in this case they would come from a tradtition of oral transmission I believe. Maybe it can relates to the music of transe they put themselves or a third party in in order to achieve a particular effect or even communicate with/reach outer spaces.
Giving a litteral meaning to what you sing by transforming these sounds into words will be fundamentally a complex endeavor because many questions might be difficult or even impossible to answer in order to find solutions.
Whatever the case if you think that something is speaking through you, or if these sounds come from within yourself, they might not be words, the language might not be human, maybe these sounds are concretions of words, maybe these words don't exist yet, maybe it's beyond words etc...
If this music is driving you mad because you don't find its profound significance, then it might help you to create a meaning by approximating the translation I would say, find these words that could translate that deep emotion you are feeling when you sing "Stella nūmen a", this way you become also poet. Or you can leave it be and accept that there will be no exact meaning or no meaning at all.
Either way you have found a succession of sounds that moves you, it is a little musical pearl just for you.
I hope it was helpful ☔