Can something come from nothing

[pocaracas]

No, the question can't be that... at least not with the "now" attached.
At any time, there is, at least, time. And time is manifestly not nothing.

With out the "now" detail, "why is there anything at all?" may be a too ambitious question, as we clearly don't have the necessary skill to answer it satisfactorily.
I'd prefer to first tackle the big bang event, if space-time exists beyond the Universe and how far it extends and then we may be in a better position to answer that first question.

I used the qualifier 'now' because the 3W is about the ability of things to sustain their own existence, i.e. creation is the constant coming into being.

Well then, the question is malformed.
For as long as there is time, there is never nothing.

You may ask "Why is there matter and energy, rather than just plain empty space-time?", but that is a different question.
Space-time is not nothing.... it is something.
And it is something that has been proven to actually generate energy and matter, so that problem has been solved for us a few decades ago.


But it seems like you are looking into the fact that this energy and matter retain their existence within this space-time framework. As time goes on, things remain - there's a continuity - energy and matter are conserved (for the most part)...
Why is energy conserved? I don't know... I'd much rather ask "How is energy conserved?" The 'Why' implies a reason, some intellect that thought about it and decided it to be so... when you ask that 'why' question, you are, in essence, poisoning the well.
For energy to not be conserved, one would have to find a mechanism for energy to be lost.... to be reclaimed by the quantum foam... but no such mechanism has been discovered, yet (as far as I know). Until then, the observation is that energy is conserved. How? Through the absence of energy sinks.
What property of space-time inhibits the existence of such energy sinks? I don't know.... that is way beyond my pay-grade. And (as far as I know) no one can answer that.... at least, yet.